64 PROCEEDINGS OF THE ACADEMY OF 



It may be doubted whether Mr. Lea's first name will not eventually prevail, 

 since, before he published Schizostoma, Bronn's genus of the same name 

 (Lethea Geogn. i. 95, 1835-1837), had been called a synonym of Bifrontia 

 (Omalaxis) of Deshayes. {Vide Desh. in Lam. ix. p. 104.) Indeed, H. and A. 

 Adams (Gen. Rec. Moll. i. 305) do not appear correct in giving preference to 

 Gyrotoma over Schizostoma, Lea, on account of Schizostoma, Bronn, since (on 

 p. 244) the latter name is placed in the synonymy of Omalaxis. 



Another generic name Schizostoma is quoted in Hermannsen's Index. I have 

 not obtained access to the work containing this description, but its date is said 

 to be anterior to Mr. Lea's description. 



Mr. Lea's second name, Schizochilus, had previously been used in Coleoptera 

 but withdrawn before Mr. Lea's description was published. 



Mr. Shuttleworth, in July, 1845, (Mittheilungen der Naturforschenden Ge- 

 sellschaft in Bern, p. 88,) gives another description of the genus under the 

 name of Gyrotoma, founded on two species from the Coosa River, description? 

 of which are also given. 



The generic name of Mr. Shuttleworth has been adopted in H. and A. Adams' 

 Genera of Recent Mollusca (i. p. 305, Feb., 1854.) 



Dr. Gray also (Guide to Mollusca, i. p. 103, 1857) adopts Shuttleworth's 

 name. 



Such being the confused state of the synonymy of the genus, we have decided 

 to adopt, at least temporarily, the earliest name concerning which no doubt 

 exists. 



Only about ten species of this genus have as yet been published, eight of 

 which are by Mr. Lea in 1842 and 1845, since which time few specimens have 

 been collected, and but two new species added. I now propose to add descrip- 

 tions of nine new species to the number already known, in one of which, " G. 

 salebrosa," we note a character not hitherto observed, except in what was per- 

 haps the original type of the genus, viz., a nodulous coronation upon or near 

 the suture, which nodules by lateral compression assume the form of folds or 

 plaits, thus approximating the longitudinal ribs of Gyrotoma costata, Swainson. 

 Gyrotoma bulbosa, nob., herein described, also exhibits this character, though 

 far less decidedly; and as specimens become more common, we may hope to 

 re-discover the original type so long unknown. 



Gyrotoma kecta, Anthony. Shell smooth, cylindrical, yellowish, thick ; 

 spire short, originally furnished with about 5 low whorls, of which 3 are nearly 

 lost by truncation ; fissure moderately broad, not quite direct and not re- 

 markably deep ; sutures lightly impressed ; aperture narrow ovate, occupying 

 about 3-5ths of the length of the shell; within dusky and obscurely banded ; 

 columella callous, thickened abruptly at the fissure. 



Length of shell 11-16 in. Length of aperture 7-16. Breadth of shell in. 

 Breadth of aperture 3-16. 



Hab. Coosa River, Alabama. My Cabinet. 



06s. This is the most cylindrical species I have ever seen in this genus. 

 In its general form and coloring it most nearly resembles G. demissa, nob., but 

 is longer, more elevated, smoother, and is ornamented with bands, which on 

 that species are entirely wanting ; these bands on the body whorl are three in 

 number, of which the middle one is the narrowest and least distinct ; they are 

 widely distant from each other ; the cord-like cincture is very prominent in 

 this species and the fissure is farther removed from the suture than is usual . 

 It is altogether a beautiful and graceful species. 



Gyrotoma demissa, Anthony. Shell short, robust, thick, truncate, of a 

 dark horn color ; spire flat by truncation, exhibiting traces of about four 

 whorls ; body whorl cylindrical ; .fissure broad, waved, and rather deep : 

 aperture elliptical, within whitish ; columella thickened along its whole ex- 

 tent, but most so at the fissure. 



Length of shell 10-16 in. Length of aperture 7-16. Breadth of shell 7-16. 

 Breadth of aperture 4-16. My Cabinet. 



[Feb, 



