ISSN:0368-2935    

DOI:10.1111/j.1096-3642.1956.tb02504.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

Summary.The flight of various species of Hydradephaga is recorded.An account is given of the flight muscles and their skeletal supports in anAgabuscapable of flight.The reduction of the flight muscles and the modifications of the metathorax inAgabus undulatusare described. The first pair of abdominal spiracles, adjacent to the metatergum, is smaller than in a flying beetle of comparable size, and the anterior abdominal tergites are pale and membranous.While the wings ofA. undulatusare reduced in size, the dark intercubital plate, so characteristic a feature of the Dytiscid wing, shows no parallel reduction, and Heberdey's view of its function as one of the ‘ locking’ devices of the elytra is discussed.There is some evidence to‐ suggest that in the genusAgabusspecies with narrow metasternal, wings are flightless.An account is given of flight reduction inAgabus labiatus, A. uliginosus, Lacco‐philus hyalifvus, Hygrotus quinqudineatusandllybius fenestratus.The possible bearing of these observations on the distribution of species is discussed, and the view is expressed that incapacity for flight may help to explain the local distribution of certain species frequenting standin

ISSN:0368-2935    

DOI:10.1111/j.1096-3642.1956.tb02505.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

Summary.1A single living specimen ofBrechites penis(L.) was obtained at low water mark on a sheltered beach on Singapore island in March 1954.2With the exception of a small area near the anterior end, where the pallial muscles are inserted into the shell, the remainder of the animal is separated from the calcareous tube by a continuous sheath of periostracum.3The posterior adductor muscle is absent, and the anterior adductor is reduced to four small muscle bundles. This condition is described as ‘ amyarian ‘. There are no retractor muscles of the visceral mass, nor does the surface of the visceral mass contain any muscle fibres. The pallial, and siphonal muscles are highly developed.4The ciliary sorting and cleansing mechanisms on the ctenidia, labial palps, visceral mass and mantle are figured and descri

ISSN:0368-2935    

DOI:10.1111/j.1096-3642.1956.tb02506.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

SUMMARY.A new genus of platyctenid Ctenophore is described and is shown to be intermediate in structure betweenCoeloplanaandLyrocteis.It is shown to form a further step in the series from free‐living to sessile forms, and to furnish additional proof that the Platyctenida are specialized offshoots of the ctenophore stem and not intermediate between Ctenophora and Platyhelminthes. A new definition of the order Platyctenida is give

ISSN:0368-2935    

DOI:10.1111/j.1096-3642.1956.tb02507.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

SUMMARY.An account is given of the Cladocera collected at Prapat, Lake Toba, during a month spent there in the summer of 1953. The collections are compared with those made by the Deutsche Limnologische Sunda‐Expedition. Notes are made on the systematics of the species collected, and the paper concludes with a general ecological not

ISSN:0368-2935    

DOI:10.1111/j.1096-3642.1956.tb02508.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

ISSN:0368-2935    

DOI:10.1111/j.1096-3642.1956.tb02508a.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY