394 BULLETIN OF THE 



The brownish tint of the single specimen may be accidental; when fresh, it 

 is probably white. 



Cyclostrema pompholyx n. s. 



Plate XXVIII. Fig. 9. 



Shell white, polished, thin, with three rounded, rapidly enlarging whorls. 

 Sculpture of tine incremental strias; suture deep but not channelled; whorls 

 very round, but the spire hardly rising above the last whorl; base rounded, with 

 a very narrow umbilicus, into which the whorl descends without any angle or 

 other change of curve; aperture large, circular, the upper part a little angulated 

 at the suture, margin simple, sharp, somewhat expanded but hardly reflected. 

 Max. diam. of base, 4.2; min. diam., 3.0; alt., 3.0 mm. 



Habitat. Station 2, Gulf of Mexico, in 805 fins. 



I am in doubt as to the generic place of this species, so simple in its charac- 

 ters and without the soft parts. I had thought of putting it under Choristes 

 or with Vitrinella, and finally, in placing it here, feel by no means satisfied 

 that the choice is a correct one. 



Cyclostrema cistronium n. s. 



Shell small, white, with a polished nucleus, one and a half rounded and as 

 many more carinated whorls; spire depressed; radiating sculpture of fine close 

 flexuous threads, which appear chiefly in the interspaces of the spirals, giving 

 the surface a minutely punctate appearance; these extend over the whole sur- 

 face except of the nuclear whorls; spiral sculpture of on the summit seven 

 or eight, between the carina? six or eight, and on the base ten or fifteen ex- 

 tremely fine threads, even and uniform, with about equal interspaces, some a 

 little granular from the radiating sculpture; beside these there are three very 

 strong carina?; one furms the margin of the nearly flat spire, the second extends 

 horizontally just below the periphery, the space between them deeply ex- 

 cavated; the third forms the edge of the funicular narrow deep umbilicus. 

 The base is conical, excavated just within the peripheral carina; it rises to the 

 edge of the umbilicus, w T hich is marked by a strong thread, and within is 

 vertically striated. The last whorl descends from the general plane, and finally 

 becomes separated from the body wdiorl ; the margin is simple, sharply angu- 

 lated by the carinations, otherwise the aperture would be ovate, with the colu- 

 mellar side somewhat excavated. Alt., 1.6; max. diam., 2.0 mm. 



Habitat. Off the coast of North Carolina, in 22-63 fins., sand and gravel, 

 in the warmer area. 



This is a very strongly marked species, in its sculpture recalling C. Vcrreauxi 

 Fischer, which is larger, less elevated, with a proportionally larger umbilicus, 

 and has not the deflected aperture. The latter recalls the characters of Tubiola 

 divisa J. Adams, which is otherwise very different. 



