XXIV 



tion of the aperture, I was not aware that M. Bronn 

 had ah-eacly used that name for a fossil genus. I 

 now propose to substitute Schizockilus.'' 



In the Proceedings of the Academy of Natural 

 Sciences of Philadelphia, 1860, p. 63, Mr. John G. 

 Anthony makes some lengthy remarks on this genus, 

 as follows : — 



" Gyrotoma. As some confusion exists regarding the name 

 of this genus, the following notes are given : — 



"The genus Melatoma was established by Swainson, and 

 first given to the world in 1840, in his 'Treatise on Shells 

 and vShell Fishes,' published in London, founded, as he sa^'s 

 (p. 202), 'upon a remarkable Ohio shell sent him many years 

 before by his old friend, Prof. Rafinesque.' 'It has,' he 

 remarks, ' the general form of a Pleurotoma and of a Melafu- 

 sus, with a well-defined sinus or cleft near the top of the outer 

 lip, while the inner, though thin, is somewhat thickened above.' 

 The other characters named by him are such as are generallj'' 

 considered rather specific than generic, and the pleurotomose 

 cut in the outer lip, as applied to a fluviatile univalve, is alto- 

 gether insufficient to indicate a new genus. The specimen 

 aliuded to by Swainson, and from which his generic description 

 was drawn, was an imperfect one ; and the species has not 

 since been identified by American naturalists. This is less to 

 be wondered at when we consider how very local the genus 

 has always been, and how few specimens have found their way 

 into our collections. The waters of Alabama have, as yet, 

 monopolized this interesting genus ; and it is probable that 

 even there it is confined almost if, not quite, exclusively to 

 the Coosa and its tributaries. 



"On p. 342 Swainson gives the following generic descrip- 

 tion, adding a figure : — 



" ' Fusiform, longitudinally ribbed ; a deep sinus at the top 

 of the outer lip ; base contracted ; channel wide.' 



"Mr. Swainson's figure is quite unsatisfactory. His genus 

 3Matoma is referred doubtfully to Clionella by H. & A. 

 Adams, and has not prevailed for this genus in America or 

 Europe. I have, therefore, decided not to make use of it in 

 this case. 



" Subsequently this genus has been noticed by various 

 authors, and other names have been applied to it. In 1841 or 

 1842, Dr. J. W. Mighels sent me specimens of one species, 

 under the name of Sipella scissura; but his generic name was 

 never published, and his species, if not identical with any 

 which Mr. Lea afterwards described, seems to have been over- 

 looked and forsotteu. 



