382 Rev. A. M. Norman on the 



were the same as Linm^'s species ( Jl per^jerse^s), and belonged 

 also to the genus ClausiUa, and because the T. hidens of 

 Montagu was not the Linnean species of the same name, 

 Pultenej's name of nigricans should be adopted as being 

 older than that of Draparnaud. But at that time I had no 

 opportunity of consulting the original edition of Pulteney, 

 which appeared in 1799 ; and I concluded that the second 

 edition (1813) recapitulated the specific names given in the 

 original edition. I subsequently found out my mistake. 

 The present species is the Turho perversus of Pulteney, 1799 ; 

 and that name is prior to rugosa. T. perversus^ Linn^, is the 

 type of the genus Balia. The specific name nigricans was 

 first published by Maton and Rackett in 1804 ; Draparnaud's 

 name rugosa dates from 1801. See Brit. Conch, i. pp. 278 

 and 280. 



Valvata piscinalis, Miiller. 



Mr. Groves has generously presented me with a reversed 

 or sinistrorsal specimen from Sunbury. This kind of mon- 

 strosity occurs in probably every species of turbinated or 

 spiral univalves, as well as in some bivalves. 



XLII. — " On the Willemoesia Group of Crustacea.''^ 

 By the Rev. A. M. Norman. 



Mr. Spence Bate has a paper on a very interesting series of 

 new Crustacea, from the ' Challenger ' expedition, in this 

 month's ' Annals.' I do not see my way at present, how- 

 ever, to acquiescing in his conclusions, and therefore ven- 

 ture to ask him to give us some further information. 



1. Are his genera Pentacheles and Willemoesia any thing 

 more than the other sex of Polycheles ? Has not my friend 

 mistaken sexual for generic character's ? Has he male and 

 female of any Polycheles or any Pentacheles ? and if so, will 

 he let us know how these sexes are distinguished ? Judging 

 from his descriptions, I should say that Polycheles Helleri and 

 Pentacheles euthrix are the two sexes of the same species. 

 Can he prove that they are not ? 



Two Crustacea dredged by the '■ Porcupine ' expedition of 

 1870 off the Spanish coast are before me. I consider them 

 male and female of Polycheles typhlops, Heller ; but the one is, 

 according to Bate, a member of another genus {Pentacheles) 

 diflfering from Polycheles in having the last pereipods chelate, 

 a deeper notch on each side of the front of the carapace, and 



