III. — Revision op the Marine Gastropods referred to Ctclos- 



TREMA, AdEORBIS, ViTRINELLA, AND RELATED GENERA ; WITH DE- 

 scriptions of some new genera and species belonging to the 

 Atlantic Fauna of America. By Katharine Jeannette Bush. 



In studying the descriptions and figures of the many species of 

 marine gastropods from various and widely separated localities, 

 which have been referred to Gyclostrema, Adeorbis, Vitrinella, and 

 related genera, I soon found that there was great variation in their 

 form, texture and sculpture. It seemed to me that the most satis- 

 factory and permanent results toward eliipinating this confusion 

 would be gained by publishing the original descriptions of the 

 various genera, with their types, for convenience in deciding the 

 relations of the species already known. 



In the present article, therefore, I have given descriptions of the 

 genera, arranged chronologically, with lists of the species belonging 

 to the marine fauna of eastern America, which have been correctly 

 or incorrectly referred to them, together with several new genera 

 and species. When possible, I have also given figures of the type 

 species of each genus. 



In carrying on these investigations I have been greatly aided by 

 Professor A. E. Verrill, of Yale University, Dr. W. H. Dall, of the 

 U. S. National Museum, and Mr, E. A. Smith, of the British 

 Museum. 



Cyclostrema Marryatt, 1818. Type, C. cancellata Marryatt. "West Indies ? 



Plate XXir. figs. 4, 4a. 

 " Cyclostrema.''^ 

 " Character genericus." 



" Testa depressa, perspectivo-umbilicata ; apertura circularis." 

 " C. cancellata Marryatt." 

 " Tab. X, Figs. 3, 4." 

 " C. testa alba, lineis longiludinalibus et transversis elevatis decussantibus, inde 



cancellata. Habitat ." 



" Apertura labiis cancellatis, cancellis tranversim striatis." 



" I found this beautiful little shell among a collection of chiefly 

 West Indian Shells. According to the Linnaean system, it would 

 come under the genus Turho,''^ etc., etc. Trans. Linn. Soc. London, 

 xii, p. 338, 1818. 



Trans. Conn. Acad., Vol. X. July, 1897. 



7 



