摘要:

The Ctenoplectridae (for the generaCtenoplectraandCtenoplectrina) are separated from the Melittidae, in which they have commonly been included. Ctenoplectrids differ from melittids in many characters, and are more closely related to the long‐tongued families Fideliidae, Megachilidae, Anthophoridae, and Apidae than to the Melittidae and other short‐tongued families. Ctenoplectrids are the sister‐group of the long‐tongued bees (and could be considered as long as long‐tongued bees with labial palpi of short‐tongued bees); melittids are the sister‐group to the ctenoplectrids plus long‐tongued bees. Characters are listed that support these relationships.Ctenoplectraspecies appear to be oil collectors from flowers of curcurbits. Some behavioural observations are included.Ctenoplectrinais a probable parasite in nests ofCtenoplectra, as it lacks the pollen and oil manipul

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1980.tb01122.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

A now genus and species of large (up to 38 mm) arborescent foraminifer was found in abundance (100/m2) in an ice‐covered embayment of the Ross Sea, Antarctica. In contrast to highly productive adjacent areas, this oligotrophic embayment is bathed with water coming from beneath the extensive Ross Ice Shelf. Analyses demonstrate no primary productivity and very low bacterial populations in the water column: however, benthic diatom productivity and bacterial populations are substantial. This arborescent foraminifer is well adapted to these unusual conditions. It is of complex construction with a subcentral double‐walled bulb, a dendritic root system, and a stem which gives rise to branches. The bulb and root system reside in the sediment. The stem extends from the top of the bulb through from I to 3 mm of sediment into the overlying water, where it terminates in branches. Laboratory andin situobservations have demonstrated that the organism captures bottom sediments, which are brought into suspension by the activities of larger benthic invertebrates, in cytoplasm extending from the branches and stem. Examination of cytoplasmic composition and arrangement indicates that feeding lakes place infrequen

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1980.tb01123.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Recent collections of living material of all the known British species of the family Tergipedidae have enabled a re‐evaluation of the significant taxonomic features.Precuthona peachi(Alder&Hancock 1848) is shown to be the fully adult form ofCuthona nana(Alder&Hancock, 1842), although there is evidence of geographical divergence in behaviour and development processes near the western limit of its range on the North American seaboard.Cuthona pustulata(Alder&Hancock, 1852) is found to possess a penial stylet. The investigation of abundant European material ofC. pustulataand seven further species ofCuthonaprovides a new basis for interspecific discriminatio

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1980.tb01124.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The family Margaritiferidae has received little serious anatomical study since the early twentieth centurv. The present paper attempts to provide information, derived from relaxed preserved and living material, on aspects of the mantle anatomy and neuroanatomy of two species,Margaritifera margaritiferaandCumberlandia monodonta. An historical overview of the systematics of the family is provided along with a proposed division of major groups within the genusMargaritifera.The diaphragm of margaritiferids is complete, rather than incomplete as previously interpreted, and is formed bv both the gills and the diaphragmatic septa, the latter of which, in life, cover a portion of the posterior outer gill demibranchs and separate the branchial and suprabranchial chambers. Union of the diaphragmatic septa posteriorly draws the mantle margins together, separating the inhalent and exhalent apertures and thus completing the diaphragm.The general visceral nervous system of each species is consistent with that of other bivalves. Differences from other unionaceans include the possession of a small, as opposed to a large, dorsal supra‐anal bifurcation. Also, each of the two species studied lacks the anterior loop of the branchial nerve reported in some other unionacean

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1980.tb01125.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY