MUSEUM OF COMPARATIVE ZOOLOGY. 361 



occasionally present a great resemblance to specks of Vitrinella and some 

 Ethalias. But when the species are all definitely allotted their proper place 

 from a complete knowledge of their characters, there can be no doubt most of 

 these discrepancies will be cleared away. 



There are a number of species of these small forms on the eastern coast of 

 the United States, in addition to the probably large number, some of which 

 have been described, which inhabit the Antilles. Thus we have Ethalia 

 •multistriata Verrill, extending from Dominica to North Carolina; E. reclusa 

 Dall, found on the coasts of Yucatan and North Carolina; E. suppressa Dall, 

 West Florida , E. solida Dall, from Cuba, also probably Floridian ; Teinostoma 

 (Pseudomelia) semistriata Orbigny, Key West; T. cryptospira Verrill, North 

 Carolina; Vitrinella multicarinata Stimpson, North Carolina; Cochliolepis 

 parasitica Stimpson, South Carolina; C. striata Stimpson, Florida; Adeorbis 

 Beaui Fischer, Florida; A. naticoides Dall, North Carolina; and A. supra- 

 nitida Wood, with its varieties, from the whole Atlantic coast south of Cape 

 Cod. Trochus cancellatus Jeffreys is probably a Cycloslrema or Adeorbis, in- 

 stead of a Machceroplax as he suggested. We have it from 1000 fathoms, off 

 the coast of Yucatan. Tharsis Jeffreys is, from an examination of the typical 

 species, nothing more than a synonym of Ethalia, as here understood, or at 

 most a feebly characterized section of Ethalia. 



Subgenus ETHALIA H & A. Adams. 

 Ethalia reclusa n. s. 



Plate XXVIII. Figs. 1, 8. 



Shell small, when fresh vitreous transparent white, of three visible whorls, 

 the last much the largest, smooth and polished above, or with only faint incre- 

 mental lines below; periphery rounded, spire and base moderately rounded; 

 margin of last whorl appressed at the suture so that the thin edge runs up 

 over the preceding whorl and the real suture is almost invisible in fresh speci- 

 mens ; the outline of the preceding whorl being visible through the shell, 

 the appearance of a suture is presented much nearer the periphery than the 

 suture really is. Aperture nearly circular, oblique; the columella thick, ap- 

 pressed ; umbilical callus sparse, not polished, in adolescent specimens not quite 

 complete. Alt. 1.0, max. diam. 2.1 mm. 



Habitat. Yucatan Strait, 640 fms. Coast of North Carolina, in 12 to 63 

 fins., U. S. Fish Commission, on sandy and gravelly bottom, in the warmer 

 area. 



This species is nearest Ethalia diaphana Orbigny, so far as the base is con- 

 cerned, but resembles E. anomala Orbigny in its upper surface, and was inad- 

 vertently referred to that species in my Preliminary Report (Bull., IX. p. 52). 

 It has, however, a more elevated shell and a proportionately larger last whorl, 

 while. E. anomala has no basal callus over the umbilicus. 



