Showing papers in "Journal of Natural History in 1985"
TL;DR: Information presented supports the hypothesis that egg sacs are an effective barrier against scavenging predators (generalists), while coevolution between spiders and their specialized (highly adapted) parasitoids and predators is responsible for the specificity displayed by the latter two groups and the structural diversity evident of Egg sacs.
Abstract: The function of spider egg sacs is analysed as structures to reduce or prevent mortality by parasitoids and predators. The host relationships of the groups concerned are documented, with special reference to the Australian fauna. Many new records are presented and the biology of each group is discussed. Information presented supports the hypothesis that egg sacs are an effective barrier against scavenging predators (generalists), while coevolution between spiders and their specialized (highly adapted) parasitoids and predators is responsible for the specificity displayed by the latter two groups and the structural diversity evident of egg sacs.
139 citations
TL;DR: Reliable species separation of these larvae will be of practical value in forensic and carcase ecological studies in the wide area of the northern Holarctic.
Abstract: Descriptions based on a detailed comparative study of the structural features of all three larval instars and puparia of the six British Calliphora and single Cynomya species are given. The results demonstrate that certain characters, singly or in combination, enable reliable species separation, while some features used previously are not reliable. In the first and second instars features of the cephalopharyngeal skeleton are used for species identification while in the third instar details of the spines of the segmental bands and the structure of the anterior spiracle are diagnostic. Keys to third instar larvae and to puparia of all the above species are given. Reliable species separation of these larvae will be of practical value in forensic and carcase ecological studies in the wide area of the northern Holarctic.
77 citations
TL;DR: A cladistic analysis of the nearctic genera of Eumeninae is presented, and the first comprehensive cladogram for any significant portion of the subfamily is presented.
Abstract: A cladistic analysis of the nearctic genera of Eumeninae is presented. The ground plan states of 43 character systems are discussed, and the first comprehensive cladogram for any significant portion of the subfamily is presented. At least eight of the 26 genera are apparently nonmonophyletic: Zethus, Montezumia, Euodynerus, Odynerus, Pterocheilus, Stenodynerus, Leptochilus and Microdynerus. A key to the nearctic genera accompanies the text.
74 citations
TL;DR: In this paper, the authors studied Giraffe cow-calf relationships in the Serengeti National Park, the Arusha National Park and the Tarangire National Park.
Abstract: Many features recommend the giraffe (Giraffa camelopardalis) for behavioural study: it is big, abundant, conspicuous, active by day, reasonably trusting of people, deliberate, and the best self-marked animal in existence. Surprisingly, its social behaviour has been largely neglected. We studied giraffe exclusively for the following periods: February–March, 1975 and January–December, 1977 in the Serengeti National Park, July 1979–June 1980 in the Arusha National Park, and January–October, 1981 in the Tarangire National Park, totalling 3264 hours of observation directed principally to social behaviour. All of these parks are in northern Tanzania. An earlier paper (Pratt and Anderson 1979) presented the results of a year's investigation of giraffe cow-calf relationships in the Serengeti National Park. That study demonstrated the strength of the cow-calf bond in agreement with the findings of Langman (1977) and described in quantitative fashion the behavioural patterns and interactions of mother and young, es...
72 citations
TL;DR: It is concluded that despite its obvious specializations the Malapteruridae is basically a plesiomorphic group and that its relationships lie with some taxa belonging to the Old-World Siluridae, a paraphyletic assemblage with other included taxa having their close relationships with the Schilbeidae.
Abstract: Among siluroid fishes (catfishes), the Malapteruridae uniquely possess an electrogenic organ. Although much attention has been paid to the anatomy and physiology of the electric organ, little emphasis has been given to other anatomical characters, particularly with regard to their indicating phylogenetic relationships. Ten character complexes involving cranial bones, muscles, swimbladder connections and vertebral column are here analysed and compared with those of other siluroids. It is concluded that despite its obvious specializations (autapomorphies) the Malapteruridae is basically a plesiomorphic group and that its relationships lie with some taxa belonging to the Old-World Siluridae. The Siluridae are thus a paraphyletic assemblage, with other included taxa having their close relationships with the Schilbeidae. The evolutionary potential for development of the electric organ is accounted for by the loss of a rigid connection between the pectoral girdle and the skull and the associated modification of...
57 citations
TL;DR: A full suite of myrmecophilous organs comprising Newcomer's organs, tentacular organs and pore cupolas, has been identified in Lysandra coridon, L. bellargus and Polyommatus icarus.
Abstract: Scanning electron microscope studies have been made of larvae of eight of the fifteen resident British lycaenids (including Maculinea arion). A full suite of myrmecophilous organs comprising Newcomer's organs, tentacular organs and pore cupolas, has been identified in Lysandra coridon, L. bellargus and Polyommatus icarus. M. arion possesses Newcomer's organs and pore cupolas. Quercusia quercus has pore cupolas and what may be the rudiments of tentacular organs. Strymonidia pruni and Hamearis lucina have only pore cupolas. No myrmecophilous organs were identified on larvae of Cupido minimus, but poor quality material suggests this may be artifactual. The ultrastructure of the myrmecophilous organs or their supposed homologues is described in detail. The results presented are compared with those of earlier authors for the other seven resident species of British lycaenids. The functions, homologies and possible evolutionary origins of the myrmecophilous organs are discussed.
49 citations
TL;DR: The following digeneans are described, recorded or figured from South African waters: Phyllodistomum tongaatense sp.
Abstract: The following digeneans are described, recorded or figured from South African waters: Phyllodistomum tongaatense sp. nov. from Coracinus multifasciatus; Steganodermatoides [= Proctophantastes] allocytti comb. nov. (syn. Hudsonia pacifica) from Neocyttus rhomboidalis; Overstreetia sodwanaensis gen. et. sp. nov. from Pranesus pinguis; Cephaloporus bakeri sp. nov. from Pervagor melanocephala; Stephanostomum (?) solontschenki from Merluccius capensis; S. ditrematis from Megalaspis cordyla; Stephanostomum. spp. metacercariae from Merluccius capensis and Chaetodon marleyi; Lepidapedon (Lepidapedoides) nicolli from Epinephelus albomarginatus; Holorchis pycnoporus (syns: legendrei, ioannoui) from Sparodon durbanensis and Diplodus sargus; Pseudaephnidiogenes rhabdosargi from Rhabdosargus sarba and R. holubi; P. rossi sp. nov. from Caffrogobius nudiceps; Clavogalea gaevskayae gen. et sp. nov. from Trachinotus botla. The following other taxa are discussed: genus Steganodermatoides (syns: Hudsonia, Allosteganoderma);...
38 citations
TL;DR: An identification guide to the genus Eurysternus is presented, and one new species, confusus is described from South America.
Abstract: An identification guide to the genus Eurysternus is presented. One new species, confusus is described from South America. The synonymies inflexus (Germar) (=planipennis Lucas), parallelus Castelnau (=femoralis Lucas), hirtellus Dalman (=cirratus Harold), calligrammus Dalman (=opacus Lucas), foedus Guerin-Meneville (=claudicans Kirsch), velutinus Bates (=hypocrita Balthasar), and caribaeus (Herbst)(=peruanus Harold) are established, and four previously established synonymies confirmed. Lectotypes are designated for the following species of Eurysternus: mexicanus Harold, plebejus Harold, angustulus Harold, velutinus Bates, hypocrita Balthasar, hamaticollis Balthasar, nebulosus Kirsch, peruanus Harold, sulcifer Balthasar, cirratus Harold, planipennis Lucas, cyanescens Balthasar, femoralis Lucas, and for Onitis deplanatus Germar. Neotypes are designated for the following species of Eurysternus: magnus Castelnau, marmoreus Castelnau, impressicollis Castelnau, foedus Guerin-Meneville, hirtellus Dalman, opatrinu...
38 citations
TL;DR: A comparative study on the development of Senegalese isolates of Schistosoma curassoni, S. haematobium and S. bovis in hamsters is reported, together with the compatibility of these parasites with Bulinus spp.
Abstract: A comparative study on the development of Senegalese isolates of Schistosoma curassoni, S. haematobium and S. bovis in hamsters is reported, together with the compatibility of these parasites with Bulinus spp. and enzymes of adult worms. The mean worm return from 35 hamsters exposed to 100 cercariae each of S. curassoni was 11·5%, and of these 54% were paired, the remainder were single males. The growth and maturation of the worms were recorded from 40 to 100 days. The cross-over point (when paired females are of the same length as paired males) was reached at 42 days post-infection when the worms averaged 13·7 mm in length. The majority of tissue eggs (84·5%) were recovered from the liver, compared with 11% in the colon, 2·5% in the caecum and 1·6% in the small intestine. Estimates of the fecundity of paired females averaged 167 eggs/day per female worm. Snail-infection experiments showed S. curassoni to be compatible with B. umbilicatus, marginally compatible with B. senegalensis and incompatible with B...
37 citations
TL;DR: The brachycnemic zoanthid genus Isaurus is characterized and its synonymy reviewed and some details are given of a sublittoral habitat and specimens from northeast Australia.
Abstract: The brachycnemic zoanthid genus Isaurus is characterized and its synonymy reviewed. Two species were found on exposed intertidal reefs in Fiji. One is identified as I. tuberculatus Gray, here revealed as almost cosmopolitan within and just outside the tropics and considered to include the nominal Caribbean species I. duchassaingi (Andres), the East African I. spongiosus (Andres), the Australian I. asymmetricus Haddon and Shackleton, and the Hawaiian I. elongatus Verrill. Though generally characteristic of reef-top environments, some details are given of a sublittoral habitat and specimens from northeast Australia. The second reef species is described as I. maculatus sp. nov. I. cliftoni (Gray) is the third species recognized although the holotype cannot be traced. Subsequent records of this species are clarified. The three species are described and two illustrated.
36 citations
TL;DR: Twenty-seven new species of Agromyzidae are described from Kenya and two from Uganda in the genera Melanagromyza, Ophiomyia, Tropicomyia and Agromyza and the following new combinations are established.
Abstract: Twenty-seven new species of Agromyzidae are described from Kenya and two from Uganda in the genera Melanagromyza, Ophiomyia, Tropicomyia, Agromyza, Cerodontha, Liriomyza, Phytoliriomyza, Napomyza, Phytomyza and Chromatomyia. The following new combinations are established: Cerodontha (Butomomyza) cariciphaga (Spencer 1963), Cerodontha (Butomomyza) pubicata (Spencer 1959), Napomyza eximia (Spencer 1964a) and Chromatomyia anonera (Seguy 1951); in addition Phytomyza natalensis Spencer 1964 a is raised to specific status. New records are given of the important pest species Ophiomyia spencerella and Liriomyza trifolii. The distribution of Kenyan species within Africa is discussed and the Palaearctic origin of new, high altitude species from Mt. Kenya is documented.
TL;DR: The old county of Yorkshire provides a diversity of habitats for freshwater crustaceans and eight species of Daphnia (Cladocera: Anomopoda) are recorded, most of which are restricted to low altitudes.
Abstract: The old county of Yorkshire provides a diversity of habitats for freshwater crustaceans. Eight species of Daphnia (Cladocera: Anomopoda) are recorded. Taxonomic problems relating to some of these are discussed where appropriate. The ecological requirements and limitations of the various species are described and the patterns of geographical distribution to which these give rise within the area are reported. Most species are restricted to low altitudes. This is not related to altitude as such, all elevations being relatively modest, but reflects the rather sharp distinction in chemistry of upland and lowland waters in Yorkshire. Upland waters are generally acidic, markedly so on moorlands, and of low ionic content, often even in limestone areas which are frequently plastered with glacial drift: lowland waters are generally alkaline and relatively rich in inorganic ions, though small areas of lowland health are exceptions. Most species are restricted to waters of the latter type. Experiments using D. magna ...
TL;DR: A reappraisal of adult taxonomy of N.E. Atlantic and Mediterranean hermit crabs upholds the divisions A & B suggested for the species by MacDonal et al. (1957) from their studies of larval features.
Abstract: A reappraisal of adult taxonomy of N.E. Atlantic and Mediterranean hermit crabs upholds the divisions A & B suggested for the species by MacDonal et al. (1957) from their studies of larval features. The nomenclature of three species is discussed. Pagurus variabilis (A. Milne Edwards and Bouvier, 1892) is relegated to the synonomy of P. alatus Fabricius, 1775 and P. excavatus (Herbst, 1791) is reinstated for Mediterranean and southern N. E. Atlantic material. A provisional check list is given of Paguroidean species occurring within the sea area 30°N–80°N:30°W–30°E and the Mediterranean Sea. An illustrated identification key is provided to the Pagurus species within these regions.
TL;DR: Three species namely Isobactrus ungulatus Bartsch, 1975; Halacarellus basteri v affinis Trouessart, 1896; and Lohmanella norvegica Viets, 1927 are new to the British fauna.
Abstract: The vertical distribution of 24 species of Halacaridae on a number of British shores is investigated. Three species namely Isobactrus ungulatus Bartsch, 1975; Halacarellus basteri v affinis Trouessart, 1896; and Lohmanella norvegica Viets, 1927 are new to the British fauna.
TL;DR: Eleven species of Gyrodactylus were found infecting five species of freshwater fishes collected from Rogate (West Sussex, England), suggesting that they colonized Britain with their hosts via the Doggerland land bridge after the De...
Abstract: Eleven species of Gyrodactylus were found infecting five species of freshwater fishes collected from Rogate (West Sussex, England). These were G. arcuatus and G. gasterostei from Gasterosteus aculeatus, G. pungitii from Pungitius pungitius, G. aphyae, G. laevis, G. limneus, G. macronychus and G. minimus from Phoxinus phoxinus, G. pavlovskyi and G. sedelnikowi from Noemacheilus barbatulus and G. rogatensis n.sp. from Cottus gobio. G. (Limnonephrotus) rogatensis is a member of the G. wageneri species group, and can be distinguished from closely related species (G. aphyae, G. pungitii and G. gasterostei) by its relatively long marginal hooks and by the abruptly tapering toes of its marginal hook sickles. Each parasite was collected from a single host species, and each was narrowly site-specific. With the exception of G. rogatensis, all of the gyrodactylids collected at Rogate also occur in Continental Eurasia, suggesting that they colonized Britain with their hosts via the Doggerland land bridge after the De...
TL;DR: In the course of a survey carried out on the digenetic trematode fauna of three species of mullets Mugil cephalus, Liza macrolepis and Valamugil cunnesius collected from various brackish water localities at Visakhapatnam, 15 species of adult digenetics trematodes and 9 species of metacercariae were encountered.
Abstract: In the course of a survey carried out on the digenetic trematode fauna of three species of mullets Mugil cephalus, Liza macrolepis and Valamugil cunnesius collected from various brackish water localities at Visakhapatnam, 15 species of adult digenetic trematodes and 9 species of metacercariae were encountered. The adult digeneans are distributed over 7 families as follows: Transversotrematidae (1), Haploporidae (6), Haplosplanchnidae (2), Lepocreadiidae (1), Gorgoderidae (1), Bunocotylidae (3) and Bivesiculidae (1). Five new species, Haploporus indicus, H. pseudoindicus, Lecithobotrys mugilis, Carassotrema bengalense and Saturnius valamugilis are described. Other species reported are: Transversotrema patialense, Pseudohapladena bengalense, Saccocoelioides martini, Haplosplanchnus purii, H. caudatus, Phyllodistomum lewesi, Crassicutis karwarensis, Saturnius segmentatus, Aphanurus harengulae and Paucivitellosus sp. The nine species of metacercariae collected from mullets belonged to 5 families: Clinostomida...
TL;DR: The lophophore and the larva of the rhynchonellid brachiopod Notosaria nigricans are described in detail using techniques of light microscopy, scanning electron microscopy and transmission electron microscope.
Abstract: The lophophore and the larva of the rhynchonellid brachiopod Notosaria nigricans are described in detail using techniques of light microscopy, scanning electron microscopy and transmission electron microscopy. The lophophore comprises two helical spirals, each capable of uncoiling and extending beyond the shell margin; the muscular system responsible is described. Occasionally sudden shell retraction amputates part of the uncoiled lophophore and regeneration occurs. The entire lophophore is covered with peculiar, and apparently unique, knobbed cilia. Their function remains obscure, but may be concerned with food capture since the lophophore of N. nigricans is unusual in being incapable of secreting mucus. The lophophore acts as a brood chamber for at least two larval stages, which generally occur in a definite orientation along the base of the filaments.
TL;DR: The structure of the female cuticular organ and seminal vesicle is described and figured for the first time in the Haploniscidae, from KOH digested preparations.
Abstract: A taxonomic study is reported on the deep-sea asellote isopod family Haploniscidae from the north-east Atlantic. Seven new species are described from the Rockall Trough, Iceland Basin and Porcupine Sea-Bight, Haploniscus aduncus, H. ampliatus, H. angustus, H. borealis, H. hamatus, Antennuloniscus diversus, A. simplex, and supplementary descriptions are given of the males of three further species, Haploniscus foresti Chardy, H. ingolfi Wolff, and Chauliodoniscus armadilloides (Hansen). An identification key encompasses all known species from the study area. The structure of the female cuticular organ and seminal vesicle is described and figured for the first time in the Haploniscidae, from KOH digested preparations.
TL;DR: The spawning behaviour and sexual dimorphism of the little known North American cyprinid fish, Notropis leedsi, is described based on observations made in laboratory aquaria.
Abstract: The spawning behaviour and sexual dimorphism of the little known North American cyprinid fish, Notropis leedsi, is described based on observations made in laboratory aquaria. Notropis leedsi is a crevice spawning species, a trait characteristic of members of the subgenus Cyprinella. Males establish breeding territories through ‘mock battles’ and defend them by chasing away intruding males or, at times, through threat displays or ‘mock battles’. Although wild-caught males are significantly larger than females, sexual dimorphism is more pronounced in the colour pattern and fin size, especially the dorsal and anal fins. The modes of spawning behaviour in the genus Notropis are reviewed. The relationship between the promiscuous mating system (polybrachygamy), the crevice spawning mode, and sexual dimorphism in N. leedsi are discussed in relation to current notions regarding sexual selection.
TL;DR: The myrmicine ant genus Triglyphothrix Forel is newly synonymized with Tetramorium Mayr, and six replacement names are proposed for the secondary homonyms resulting from this synonymy.
Abstract: The myrmicine ant genus Triglyphothrix Forel is newly synonymized with Tetramorium Mayr. Six replacement names are proposed for the secondary homonyms resulting from this synonymy.
TL;DR: Eclosed larvae and fully developed embryos are found within the expanded lateral oviducts, bursa copulatrix and vagina of the putative myrmecophiles Pseudomorpha angustata and P. hubbardi, implying that larviposition is timed to coincide with summer rains.
Abstract: Ovoviviparity is reported for the first time in the ground beetle family Carabidae. Eclosed larvae and fully developed embryos are found within the expanded lateral oviducts, bursa copulatrix and vagina of the putative myrmecophiles Pseudomorpha angustata and P. hubbardi. Eclosed larvae do not appear to be active while held inside the female prior to larviposition. Maximum larval numbers occur from mid-July to early September in these Arizona species, implying that larviposition is timed to coincide with summer rains. Larviposition is hypothesized as a means to eliminate egg mortality due to predation by ant hosts.
TL;DR: A key is provided to the 15 species of Ooencyrtus recognized as occurring in the Neotropical region and the following species are described as new: caligo, syrphidis, calpodicus, caribeus, castneus, eversi and pinguis.
Abstract: A key is provided to the 15 species of Ooencyrtus recognized as occurring in the Neotropical region The following species are described as new: caligo, syrphidis, calpodicus, caribeus, castneus, eversi and pinguis; Echthrodryinus saccharalis Gordh and Trjapitzin is transferred to Ooencyrtus; Ooencyrtus trinidadensis venatorius Vidal and De Santis is given species status and Ooencyrtus fasciatus Mercet is treated as a doubtful record for the region All available published information on the biology and distribution of each species is listed and the pest status of some of the hosts is also included
TL;DR: Planococcus pacificus is shown to occur commonly on cacao in the Neotropical Region as well as in the Australo-Oriental and Polynesian Regions, suggesting that many records of P. citri from the neotropics refer to this species.
Abstract: A key and illustrations are provided for the identification of the species of Planococcus which occur on cacao. P. celtus and P. lamabokensis are transferred to Planococcoides. Planococcus pacificus is shown to occur commonly on cacao in the Neotropical Region as well as in the Australo-Oriental and Polynesian Regions, suggesting that many records of P. citri from the neotropics refer to this species.
TL;DR: What seems likely to be the first published record of a foraminiferan protozoan epizoic on an isopod (Astacilla longicornis) is reported from material collected by divers off the Berwickshire coast (Scotland).
Abstract: What seems likely to be the first published record of a foraminiferan protozoan (Cibicides lobatulus) epizoic on an isopod (Astacilla longicornis) is reported from material collected by divers off the Berwickshire coast (Scotland). Notes are also provided on other epibionts and a comparison is made with Astacilla from the Clyde Sea area which proved to have a much lower incidence of fouling. There, fouling was due largely to the entroproct Barentsia sp. and the hydroid Clytia hemisphaerica, not to Cibicides.
TL;DR: Diastopora suborbicularis Hincks (1880) is a junior subjective synonym of Alecto compacta Norman (1866).
Abstract: Diastopora suborbicularis Hincks (1880) is a junior subjective synonym of Alecto compacta Norman (1866). Eurystrotos gen. nov. is introduced for A. compacta, in place of Microecia Canu (1918). Diaperoecia Canu (1918) is restricted to its type species, Pustulopora intricaria Busk, from Australia. European species formerly referred to Diaperoecia are assigned to Annectocyma gen. nov., type species: Alecto major Johnston (1847). Annectocymidae fam. nov. is created for Annectocyma gen. nov. and Entalophoroecia Harmelin (1974).
TL;DR: All the extralimital forms of Rhysida to which previous workers have applied the specific or subspecific name nuda should not bear that name, and the name R. immarginata may be applicable to some or most of those forms.
Abstract: Of the six species of Australian Rhysida recognized by Chamberlin (1920), three are synonymized and one is excluded from Australia. Three Australian species of Rhysida are recognized: R. carinulata (Haase) and R. nuda (Newport) are redescribed, and a new species, R. polyacantha, is described. These three species are keyed, their distributions in Australia mapped, and some of their important characters tabulated together with those of two related extralimital Rhysida species, immarginata and longipes. R. nuda is confined to Australia. Hence all the extralimital forms of Rhysida to which previous workers have applied the specific or subspecific name nuda should not bear that name. The name R. immarginata may be applicable to some or most of those forms.
TL;DR: The internal structure of calceoli, in the gammaridean amphipod, Eusirus perdentatus Chevreux, has been examined for the first time using fast atom etching in conjunction with scanning electron microscopy, adding weight to the view thatcalceoli may function as phonoreceptors, sensitive to water borne pressure waves.
Abstract: The internal structure of calceoli, in the gammaridean amphipod, Eusirus perdentatus Chevreux, has been examined for the first time using fast atom etching in conjunction with scanning electron microscopy. The etching technique was used to remove surface layers of the calceolus, revealing a complex array of cuticular fibres supporting the proximal cup and distal plates. The cup was found to consist of a radial set of about 200 rod-like subunits. The results add weight to the view that calceoli may function as phonoreceptors, sensitive to water borne pressure waves.
TL;DR: The multivariate morphometric analysis used here allows the recognition of five morphological groups in Central and Southern England and, contrary to the work of Forcart, fails to distinguish between British and Swedish T. hispida.
Abstract: Trichia is a genus of pulmonate land snails that has presented problems of species discrimination. Three species are currently recognized in Britain but the multivariate morphometric analysis used here allows the recognition of five morphological groups in Central and Southern England and, contrary to the work of Forcart, fails to distinguish between British and Swedish T. hispida.
TL;DR: Two new species of physalopterid nematodes are described from a skink (Scincidae) and a gecko (Gekkonidae) from the West Australian desert.
Abstract: Two new species of physalopterid nematodes are described from a skink (Scincidae) and a gecko (Gekkonidae) from the West Australian desert. Kreisiella chrysocampa gen. et sp. nov. (Spirurida: Physaloperidae) from Egernia inornata is characterized by the possession of a row of straight parallel denticles along the medial pseudolabial margins, male caudal alae unsupported by papillae, a truncated female tail and an anteriorly-placed vulva. The original female specimen of Physaloptera heterocephala Kreis, 1940 is transferred to this genus. In Physalopteroides filicauda sp. nov. (Physalopteridae) from Nephrurus laevissimus the external apical tooth present in immature worms is represented in adults by a knob-like structure, larger on the left pseudolabium. Both sexes possess a long slender tail terminating in a small knob. The spicules are markedly dissimilar and the vulva is surrounded anteriorly and posteriorly by horizontal rows of tubercules.
TL;DR: Demonax cambrensis sp.
Abstract: Demonax cambrensis sp. nov. resembles the east Pacific Demonax medius (Bush), but is thinner though just as long and has less than 15 axial cells in a radiole cross section. Demonax torulis sp. nov. resembles Demonax japonicus (Moore) in having thoracic tori so small that they do not indent the ventral shields, but differs in having broad-hooded inferior thoracic setae. Both benefit by enrichment of the sediment with sewage sludge.