摘要:

During the past three decades knowledge of the earliest mammals has greatly increased through study of specimens of morganucodontids of Late Triassic and Early Jurassic age discovered in Africa, Asia and Europe. Communication of the results of diis research has been and continues to be impaired by disputes over the validity or content of the generaEozostrodonParrington andMorganucodonKiihne. On the basis of the limited data available and in the interest of stability of nomenclature,Eozostrodon parvusis the appropriate name for the morganucodontid represented in the fauna preserved in fissure fillings in Holwell Quarry, England. Its diagnostic dental morphology is not duplicated in the extensive samples of the most abundant morganucodontid known from Wales for which the nameMorganucodon watsoniis appropriate. Although generic reference of these species is a moot point, recognition of separate species is warranted and, with other data, points to a diverse assemblage of morganucodontids forming part of the base of a prototherian radiation.

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1979.tb01898.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Cephalops curtlfrow Coe is an internal parasite of Stenocranus minutus (Fabricius), causing mortality in the adult stage. I t is univoltine and host‐specific. Eggs are laid in the fourth or fifth instar of S. rninulus and hatch within 38 days. The first larval instars overwinter within their hosts, a period of 24–25 weeks. After diapause, they moult to the second instar. This stage is relatively short and 30–35 days later the larvae emerge from the host, to pupate in the soil or in leaf‐litter. The adult flies emerge after 18–30 days, which coincides with the presence in the field of the fourth and fifth instars of the host. Previous descriptions of C. curttfions have dealt only with the adult. Larval and pupal stages are here described in detail, together with new adult characters involving spines on the midcoxae and abdominal pleurae of the female. Parasitism i‐esults in gross distortion of the abdomen of S. minutus, causing a separation of sternites and tergites, such individuals being easy to recognize. A significant reduction occurs in femur, clasper and ovipositor size. Internally there is loss of the thoracic musculature and nervous tissue, severely restricting host movement. The sex organs are invariably affected. The spermatheca, accessory glands and ovarioles in females, and testes, sperrnathecal ducts and accessory glands in males are partially or completely destroyed. However, parasitized males with greatly reduced testes are capable of fertilization. Parasitism was found to be highest in April and May, when 16.8% of macropterous and 53.3% of submacropterous minutus contained C. curtl

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1979.tb01899.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

A new eubrachythoracid arthrodire,Hanytoombsia elegansgen. et sp. nov., is described from the Upper Devonian Gogo formation of Western Australia. Its structure and relationships are discussed within the framework provided by a new sketch cladogram for arthrodires.H. elegansis morphologically similar toCoccosteus cuspidatus, but its relationships among primitive eubrachythoracids are unknown.

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1979.tb01900.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Two newStenhelia (Stenhelia)species are described: 5.(S.) diegensisfrom 1200 m depth in San Diego Trough, California and 5.(S.) asetosafrom the intertidal of Nanaimo Estuary, British Columbia. S.(S.) diegensisdiffers from previously known species in having but one seta on the terminal segment of the P, endopod. 5.(S.) asetosalacks inner setae on the first segments of the P2–P, exopods. A table listing the salient morphological features of the species ofStenhelia (Stenhelia)is given as is a new key to the subgenu

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1979.tb01901.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

A review of the British ascophoran cheilostomes has revealed several instances of synonymic confusion, and necessitated the introduction of two new generic names.Porelloidesgen. nov. is instituted for two species formerly included inPorella, withP. laevis(Fleming) as type species, andPhaceostachysgen. nov. is introduced forLepralia spiniferaJohnson.Smittoidea amplissimasp. nov. was hitherto not distinguished fromSmittina landsborovii(Johnston).Porella minuta(Norman), reported from localities as far afield as the western Mediterranean and the Canadian Arctic, is shown to comprise two species, and the northern records are here attributed toP. albaNordgaard.Exharella labiosa(Busk) andE. klugeisp. nov. (=E.ventricosavar.peristomataKluge) are redescribed, andE. laqueataandE. abyssicolaare discussed. The case for retainingCelleporaLinnaeus is argued andLepralia quincuncialisNorman is referred toBuskeaHeller.

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1979.tb01902.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1979.tb01898a.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY