106 K. J. Bush — Marine Gastropods referred to 



" The form of the aperture would place these shells in Turho or 

 Margarita. The want of an umbilicus excludes three of the species 

 from the latter. The operculum is unknown ; but as it is extremely 

 improbable that thin, vitreous, almost transparent shells should have 

 solid calcareous opercula, we may assume it to be horny, which will 

 exclude the species from Turho^ regarding this genus as best charac- 

 terized by the operculum. The most widely umbilicated species 

 approximates in form to Skenea^ and might be mistaken for a 

 depressed umbilicated species of Helix. In texture, the nearest 

 approach among the kindred genera is in Margarita arctica 

 Leach," etc. Monograph of Vitrinella, Amherst, Mass., Feb., 1850. 



The above quotation shows the extended sense in which Mr. 

 Adams intended his genus, Vitrinella, to be taken, and he after- 

 wards added several species from Panama. 



The original list included five new species from Jamaica, without 

 mentioning any as a type, given in the following order : V. hyalina, 

 V. interrupta, V. niegastoma, Y. tincta and V. helicoidea. None 

 of these were figured until 1888, when figures of a species, named 

 V. helicoidea^ made from a specimen, were published in Tryon's 

 Manual, x, pi. 34, figs. 40-41. 



P. P. Carpenter, in 1855-57 (Mazatlan Mollusca, p. 236), men- 

 tioned the differences in the form of the many species referred to 

 this genus by C. B. Adams and himself, but did not restrict it by 

 naming any one of the above species as a type, and only stated that 

 " niegastoma is an JEthalia " and " that the indented species accord 

 better with Ethalia and Teinostoma?'' He also stated " there are 

 specimens of Y. tincta, Y. interrupta, Y. valvatoides, Teinostoma 

 minuta, and Ethalia niegastoma in the Cumingian Collection." 

 H. and A Adams, in 1858 (Gen. Rec. Moll.), were the next authors 

 to define the genus, but gave a figure of valvatoides for an example ; 

 this species, however, not being in the original list, cannot stand as 

 the type. 



I propose Y. helicoidea as the type and restrict the genus to small, 

 more or less hyaline, low-spired shells of few convex whorls, having 

 a moderate-sized, deep umbilicus ; nearly circular, oblique aperture, 

 with simple more or less continuous peritreme, modified on the 

 body-whorl into a more or less conspicuous glaze, which may 

 be absent in the young ; columellar margin often flattened in the 

 adult, having the appearance of being thickened, and angulated at 

 the lower, outer edge. 



I have a group of such shells from shallow-Avater, off Cape Hat- 



