DIASTYLIDJE. 31 



i Nordishavit," K. Svenska Vet.-Akad. Ilandl. vol. xi. p. 7, pi. iii. 

 figs. 8, 9 (young specimen). 



1900. Diastylis Rathkei, G. O. Sars, Crust. Norway, vol. iii. 

 Cuinacea, pp. 44 & 107, pis. xxxiii., xxxiv., Ixx.-lxxii. 



Falmouth (W. Webster, fide Sate) ; Plymouth, from 

 trawlers' refuse (Sate); Exmouth and Torbay (A. M. JV.). 



DIASTYLIS L^EVIS, Norman. 



1869. Diastylis latvis, Norman, " Last Report Dredging Shetland," 



Brit. Assoc. Rep. for 1868, p. 270. 

 1879. Diastylis kevis, Norman, " Crustacea Cumacea of ' Lightning ' 



&c. Expeditions," Ann. & Mag. Nat. Hist. ser. 6, vol. iii. p. 60. 

 1900. Diastylis rostrata, G. 0. Sars, Crust. Norway, vol. iii. Cuinacea, 



p. 51, pi. xxxix. (nee Alauna rostrata, Goodsir). 



Professor Sars has considered Alauna rostrata, Goodsir, to 

 be the same as D. Icevis, Norman; but before the last-named 

 species was published Bate had synonymized A. rostrata with 

 C. Rathkei, Kroyer. Which author is right? We believe 

 the latter. At first sight indeed Goodsir's figure, with its 

 perfectly smooth surface, looks more like D. Icevis. But it 

 must be borne in mind that such minutiae as a few small spines 

 on the carapace would be passed over as of no importance ; 

 and the truth of this observation is proved by the fact that 

 that excellent author Kroyer gives figures of his type Cuma 

 Rathkei which present an absolutely spineless carapace, 

 similar to the figure of Goodsir. But the figure which 

 Goodsir gives of the first peroeopod clearly shows that the 

 species he was describing was D. Rathkei and not D. Icevis. 

 The basal joint of this first perseopod is represented with a 

 spinose margin. Compare this with Sars's description of the 

 same part in the two species : I). Rathkei : " First pair of 

 legs .... basal joint .... denticulate in its distal part " ; and 

 in his " Aberrante Krebsdyrgruppe Cumacea/' 1864, he more 

 fully describes the joint : " Pedum lino paris articulus 

 basalis .... setis numerosis et plumoses ad marginem et 

 inf eriorem et superiorem obsitus dentibusque prseterea armatus 

 14-16 marginis interioris/' D. Icevis (rostrata, Sars) : " First 

 pair of legs .... basal joint densely fringed with plumose 

 setae." It is true that Norman in his description of this part 



in I). Icms wrote : " First feet with the first joint both 



margins furnished with plumose setee, spinous on the side " ; 

 but these spinules of the side are quite inconspicuous and 

 would not have been noticed by Goodsir any more than they 

 are by Sars, while the stronger spinose margin of D. Rathkei 

 seems certainly to be that indicated in Goodsir's illustration. 

 Start Bay and Salcombe (A. M. i\ 7 .). 



