摘要:

Descriptions are given of three new species of enchytraeid, each of which is recorded from several localities in Ireland. The species are compared with other members of their genera and some details of their ecology are given. The paper includes a review of the genusCernosvitoviellawith a comparison of the nine European species.

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1979.tb01107.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

The European species ofMetopinaare reviewed.M. nevadaeis synonymized withM. oligoneura, the males included in the original description ofnevadaebeing misidentifications ofM. heselhausi. M. rhenanais synonymized withM. perpusilla, the females included in the original description ofrhenanabeing misidentifications of M.oligoneura. M. pileatais added to the British List, along with a new species,M. ulrichi. Keys to both sexes of the British species are provided for the first time.

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1979.tb01108.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

The rock‐dwelling landsnailLeuantinuis represented in Israel by two species,caesareanaandhierosolyma. They are both found abundantly in Mediterranean, steppe, semi‐arid and extremely arid habitats, and are probably ancient elements in the Israeli fauna. Their common borderline shows no association with altitude, rainfall, temperature, climatic zones, lithology, phytogeography, or the distribution of predators. The possiblity that one species is actively displacing the other, and that the position of the borderline is temporary, is rejected on grounds both of previous research and of fossil finds.A narrow hybrid zone occurs in most places along the borderline. Laboratory experiments show that these hybrids are inferior to the parent species in viability and fecundity, and that assortative mating of the two parent species occurs in a mixed population. Hybridization may perhaps be maintained because selection favours the individual that will mate with its own species whenever it can tind one, but is capable of mating with other species when it cannot. In these conditions, hybridization is not a waste of reproductive energy.Certain morphological changesoccurin the vicinity of the hybrid zone. Far from the zone,caesareanaresembleshierosolymain shell‐height, shell shape and genitalia; approaching the hybrid zone it diverges fromhierosolymain these characteristics and develops a distinct variant,caesareanavar.werneri. This divergence may represent an accumulation of isolating mechanisms in the proximity of the hybrid zone, and thus be a case of reproductive character displacement. If indeed it is, then it differs from most described cases of character displacement in that the species are parapatric, not sympatric, and the displaced character is found not only at the common frontier but also from 2–12 km into the allopatr

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1979.tb01109.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

The ventral gill arch muscles of chondrichthyans,Latimeria, dipnoans, larval amphibians and actinopterygians are described and compared. Muscle patterns are characterized as primitive or derived and the derived patterns are used to test various hypotheses of the interrelationships of these griathostome groups. Gnathostomes differ from agnathans in having branchial muscles associated with the ventral gill arches. The monophyly of chondrichthyans is corroborated by the presence of coracobranchiales of hypobranchial origin. The monophyly of Recent teleostomes (Osteichthyes) is indicated by the presence of discrete transversi ventrales and interarcuales ventrales, and by the loss of the fifth superficial constrictor. A monophyletic Sarcopterygii which includesLatimeriais refuted by three paired branchial muscles found in dipnoans, Recent choanates and actinopterygians, but missing inLatimeria:pharyngoclaviculares, obliqui ventrales 1 and transversi ventrales 4. A new name, Euosteichthyes, is proposed for the group including dipnoans, choanates and actinopterygians. Sarcopterygii is restricted to include only dipnoans and choanates (among Recent organisms). Actinistia, includingLatimeria, is proposed as the sister‐group of all other Recent osteictithyans. Brachiopterygians (polypterids) are placed within Actinopterygii. A phylogenetic hypothesis supporting this classification is presente

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1979.tb01110.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Five species ofAnagrus, egg parasites of various leafhopper species (Delphacidae and Cicadellidae, Honioptera), were bred for 3–13 generations in laboratory conditions. Biological and niorphological characteristics as well as attempts at crossbreeding were used to recognise the speciesAnagrus ensijerDebauche and four new. species.A. ensiferoccurred in two varieties. The four new species and the two varieties ofA. ensiferare described, and a key is given to both sexe

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1979.tb01111.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY