186 PROCEEDINGS OF THE ACADEMY OF 



Descriptions of Fourteen new species of Schizostomae, Anculosae and Lithasiae. 



BY ISAAC LEA. 



It will be observed that I have in this paper adopted my first name (Schizos- 

 toma) for the division of those Melanida which have a cut or fissure in the 

 upper portion of the last whorl. This name I proposed in December, 1842. 

 Subsequently finding that it was used by Bronn in 1835 I abandoned it, and 

 proposed the name of Sckizochilus as a substitute, (Obs. on the Genus Unio, 

 v. 5, p. 51, 1852.) I am now satisfied that Bronn's name was applied to the same 

 g enus Euomphalus which Sowerby established in 1814, (Min. Conch, tab. 45.) 

 This evidently liberates my original name, and Herrrcannsen, in the Appendix 

 to his"Generum Malacozorum," very properly restores it. It was supposed 

 that this was the Melatoma of Swainson, and Mr. Anthony adopted this name. 

 But it is evident that Mr. Swainson's Melatoma is not my Schizostoma. By refe- 

 rence to his figure (Malacology, p. 342, f. 104) it will be observed at once that 

 there has never been observed in the United States any of the group of which 

 that figure is the type, while it is known that they exist in the islands of the 

 Indian Ocean. Mr. Swainson says (p. 202) that his Melatoma was "founded 

 upon a remarkable Ohio shell " sent by Rafinesque. Now, as no member of the 

 family Melanidce with a cut in the lip has ever been found in the Ohio, where 

 such hosts of active collectors have since pursued their investigations, it is 

 perhaps beyond the bounds of possibility that the specimen sent by Rafinesque, 

 so eminently careless and reckless as he always was, should ever have been 

 found there. Indeed, if the specimen figured was sent by Mr. Rafinesque to 

 Mr. Swainson, then the question would arise whether it had not been obtained 

 by Mr. R. from some dealer or collector, who may have obtained it from Asia. 

 I have no doubt of the Melatoma costata, which Mr. Swainson has figured, 

 being exotic, and belonging to a group probably from the Philippine Islands. 

 Mr. Anthony says, page 64, Proc. A. N. S. 1860, that "it may be doubted 

 whether Mr. Lea's first name will not eventually prevail, since, before he pub- 

 lished Schizostoma, Bronn's genus of the same name had been called a synonym 

 of Bifrontia, Desh." And that " H. and A. Adams (Gen. Rec. Moll. 1, 105) do 

 not appear correct in giving preference to Gyroloma over Schizostoma, Lea," &c. 

 Notwithstanding this, Mr. Anthony in this paper, where he describes nine sup- 

 posed new species of this genus, adopts the generic name of Oyrotoma. It may 

 be added here that Dr. Gray, in his Genera of Recent Mollusca, gives Melatoma to 

 Mr. Anthony, not to Swainson, while he does not notice the name of Schizos- 

 toma. Mr. A. does not pretend to claim it, of course, but adopts Gxjrotoma, 

 Mr. Shuttleworth's name, proposed in 1845, which being three years later 

 cannot have precedence. 



The genus Schizostoma seems to be capable of being divided into two natural 

 groups in the form of the fissura, the cut in the lip. In one group this fissura 

 is deep and direct, that is parallel with the suture or upper edge of the 

 whorl ; in the other it is not deep and is oblique to the suture. 



In Mr. Anthony's paper (Proc. Acad. Nat. Sci. Feb., 1860) I recognize several 

 of my old species. His Gyrotoma demissa I believe to be my Schizostoma con- 

 stricta. His G. quadrata to be my S. incisa. 



Schizostoma castanea. Testa, carinata, conica, subcrassa, tenebroso-fusca,, 

 imperforate. ; spira. elevata ; suturis valde impressis ; anfractibus senis, planu- 

 latis, unicarinatis, quadrivittatis ; fissura recta, angusta profundaque ; apertura 

 parviuscula, elliptica, intus vittata, ad basim subrotundata, ; columella alba, in- 

 crassata.; labro acuto, vix sinuato. 



Hab. Coosa River, Alab. E. R. Showalter, M. D. 



Schizostoma glans. Testa, laevi, ovato-conica, infiata, subcrassa, luteo-cor- 

 nea, striata, imperforate. ; spira. obtuse elevata; suturis regulariter impressis j 

 anfractibus senis, obsolete vittatis, ultimo subgrandi ; fissura recta, angusta 



[May, 



