REPORT ON THE LAMELLIBRANCHIATA. 221 



The form of this species is very variable, Imt tlie eonceiitrie ril)])in<; nnd mi('roseo])ie 

 sculpture appears to be fairly constant. 



In the Proceedings of the Zoological Society, 1881, p. 490, I gave 1841 as the 

 (late of publication of d'Orbigny's Crassatella guadaloupensis. This, as pointed out l)y 

 Mr. Dall,' appears to be incorrect. At the time I did not consult the work itself but 

 referred to Moquin-Tandon's list of authors and their works, at the end of the fii'st 

 volume of his Hist. Nat. Moll. terr. et fluv. de France. The j'ear 1841 is there quoted 

 for the issue of Sagra's Histoire de Cuba. Mr. Dall takes the first of the two species of 

 Gouldia described by Professor C. B. Adams as the type of the genus. On the contrary, I 

 think that the second species, Gouldia parva, 8\\.0Vi\(\ be retained as the type, for this 

 reason, that its adoption was confirmed by Adams himself when he descrilied another 

 species, Gouldia pacijica, belonging to the same Crassatelloid group. Notwithstanding 

 Mr. Dall's dissertation on this genus, I still maintain that Gouldia is unnecessary, an 

 opinion also shared by Mr. Boog Watson.'^ 



Mr. Dall observes that there are "abundant reasons" for separating Goxddia [cerina) 

 from Circe " on conchological grounds alone." It is unfortunate that he does not point 

 out a few of them, for, as far as I can discover from his observations, there seems to be 

 only one difference, that of sculpture. 



If difference of sculpture alone is to be held of generic importance, I think I may 

 fairly say that the genera of MoUusca might at once be doubled or trebled in number. 

 On that principle Conns cancellatus, with its strongly ridged surface, and Conus 

 marmorens, which is smooth, belong to different genera, Nassa glans and Nassa jxipillosa 

 are not congeneric, and so on in innumeral»le instances. 



A few words on the variation of sculpture in the genus C/rce may not l)e out of 

 place. Circe scripta, the type of the genus, is a flat, concentrically ridged shell with a 

 little radiating sculpture at the sides near the beaks. Circe albida is equally flat and 

 concentrically ribljcd with only the slightest trace of the lateral oblique sculpture. 

 Circe divaricata is more convex, finely concentrically ridged and ornamented all 

 over the surface with divaricate sculpture. Circe dispar is also convex, con- 

 centrically ridged, but with less ol»lic[ue sculpture. Circe lentiginosa is etpially 

 swollen as the last species, concentrically ridged, Init withinit the diverging ornamenta- 

 tion. Circe castrensis is also gibbous, more or less concentrically ridged, and is 

 painted with angular markings as in Circe scripta. Circe trimaculata and Circe 

 ccrina {Gouldia, part, C. B. Adams), are gibbous, finely concentrically ridged 

 throughout, but without angular markings. Many more forms might be mentioned, 

 which would be intermediate in respect of sculpture 1)etween some of those species 

 which I have referred to. Anyone therefore, wlm will place side by side 

 Circe scripta, Circe albida, Circe divaricata, Circe dispar, Circe lentiginosa, 



1 Bull. Mus. Cnmp. Zool, vol. ix , No. 2, p. 128. '■^ Jouni. Coiicbol., vol. iii. p. 299. 



