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NOTE ON THE OCCUERENCE OF JIETEROTANAIS 

 OERSTEDI AND OTHER ISOPODS IN CHRIST- 

 CHURCH HARBOUR, HANTS. 



By J. AND W. Omer-Cooper. 



In the course of collecting along the shore of Christchurch 

 Harbour, Hants, in May last, large numbers of small Isopods 

 belonging to the aberrant group Chelifera were found among the 

 mud and algse on the upper surface of submerged stones. Upon 

 microscopical examination these proved to be Heterotanais Oer- 

 stedi (Kroyer), a species beautifully described and figured by 

 Prof. G. 0. Sars in his ' Crustacea of Norway,' vol. ii, p. 1-i, 

 PL VI. The Rev. T. R. R. Stebbing, F.R.S., and Dr. W. T. 

 Caiman very kindly confirmed this identification, and stated that 

 they knew of no record of H. Oerstedi from the British Isles, the 

 species having been hitherto recorded from the shores of Conti- 

 nental Europe only. This species is of considerable interest on 

 account of the large size and peculiar structure of the chelae in 

 the male, which are described by Prof. Sars as follows : " Of 

 enormous size, carpus very large and produced in front, outside 

 the hand, to a lamellar lobe, hand imperfectly chelate, the thumb 

 being transformed into a thin, reflexed lappet instricted at the 

 base." 



In the same parts of the Harbour in which Heterotanais 

 occurs, two other interesting Isopods are to be found in large 

 numbers. The first of these is Cyathura carinata (Kroyer) — a 

 species closely related to the well-known Anthura gracilis (Mont.), 

 from which it differs in its large size and in several conspicuous 

 anatomical details, chief among which is the absence of the 

 secondary sexual characters seen in the male Anthura. This 

 Isopod is to be found in considerable abundance under stones 

 and burrowing in the mud ; its movements are slow, and it 

 frequently leaves the abdomen exposed above the surface of the 



