170 PROCEEDINGS OP THE ACADEMY OP 



Proceedings of the Academy in April last, the genus Sirephobasis. The genus 

 now proposed, under the name of Trypanostoma, will include all the well-known 

 Melanice, with an auger- shaped aperture, the type of which maybe considered 

 Mr. Say's Melanin canaliculata, a common and well-known species from the basin 

 of the Ohio River. It will include a number of large species, indeed, nearly all 

 of the large and ponderous species of the United States. Many new ones will 

 be found in this paper. Objections may be raised against increasing the num- 

 ber of genera without the aid of the examination of the soft parts. But there 

 is no validity in this objection, from the fact, that in the present condition of 

 the Science of Malacology, we are becoming acquainted with a vast number of 

 new and interesting forms, without the hope, at present, of seeing the soft 

 portion of the animals. These may, at some future time, and, no doubt, will 

 be examined and carefully described by Zoologists, who may dwell near the 

 waters where these numerous and highly developed species reside. Until this 

 takes place, we can only group them upon the characters which are presented 

 by their outward hard portions, which are accessible to us now. 



In proposing this new genus, I am aware that European Zoologists have made 

 many genera and subgenera in this Family, but none have made groups of our 

 numerous species by which they can be properly divided. They have mixed 

 them up, notwithstanding all the time and care they have bestowed upon them, 

 in a manner so as to make great confusion. Mr. Swainson, in his " Treatise on 

 Malacology," proposed a subgenus of Mdania under the name of Ceriphasia, 

 and gives a figure, page 204, (C. sulcata,) stating it came from Ohio. It is 

 evident, on looking on this figure, that it does not represent any Ohio species, 

 neither in the aperture nor in the revolving ribs. Dr. Gray and the Messrs. 

 Adams* adopt the genus, and the latter give a figure (pi. 31, fig. 6) of canali- 

 culata, Say, as the type, which I do not think answers to the description or 

 figure of Mr. Swainson. Dr. Gray, in his excellent "List of the genera of Re- 

 cent Moliusca," in the Proceedings of the Zoological Society, expresses a doubt 

 whether his Telescopella may not be the same with Ceriphasia. Mr. Reeve, in 

 his beautiful work," Concbologia Iconica," mixes may of our species in a man- 

 ner that does not admit of their being separated into groups ; and Dr. Chenu 

 (" Manuel de Concbyliologie'') groups together some very incongruously. 

 Many of our groups are emphatically American, and the divisions made by our 

 zoologists have not had the attention they deserve from European writers. 

 Thus, neither Dr. Gray, Mr. Reeve, nor the Messrs. Adams adopt Prof. Halde- 

 man's genus Lithasia, established so long since, and which is an easily recog- 

 nized group. Mr. Reeve puts the various species of that group into my genus 

 lo to which they certainly do not belong, and Dr. Chenu puts part of them 

 there. The genus Amnicola, long since proposed by Gould and Haldeman, for 

 a very natural group of small shells, divided from Paludina, is not recognized 

 by Chenu or Reeve. 



In a future paper I propose to define the group into which our Mclanidcs 

 seem naturally to divide themselves, adopting the well recognized genera 

 which have been established. 



Trypanostoma dcx. Testa carinata, pyramidata, crassa, rnfo-fuscescente; 

 spira valde elevata; suturis paulieper impressis ; anfractibus instar novenis, 

 planulatis ; apertura subgrandi, rhombica, intus pallido salmonia ; labro 

 acuto, sinuoso; columella incrassata et valde contorta. 



Hab. Tennessee River, W. Spillman, M. D. Fox River, Illinois, J. Sampson. 

 Oostenaula, Rev. G. White. Tuscumbia, B. Pybas. 



Trypanostoma Thortonii. Testa, carinata, pyramidata, subcrassa, cornea 



* Messrs- Adams for the type of subgenus Jvga give Buddii, Say. I am not aware 

 that Mr. Say described any Melanian under that name; and in Megara ihey give alveare, 

 Con. and basalis. Lea, as types, while they certainly belong to very different groups, 

 having very differently formed apertures. 



[April, 



