MUSEUM OF COMPARATIVE ZOOLOGY. 100 



acute, tliree-whorled, the first whorl smooth, rounded, tilted, minute; the 

 others smooth, polished, keeled on the perii)hery, alter which the remaining 

 seven whorls become sculptured ; spiral 8culi)ture of numerous regular rather 

 coarse rounded threads with equal or wider interspaces, the three most promi- 

 nent on the peripheral brown band more widely separated than the others; 

 on the anal fasciole the threads are finer and closer ; when passing over the 

 transverse ribs the threads are rarely swollen or nodulous, nor do they weaken 

 between the ribs ; transverse sculpture of (1) numerous small, gathered up 

 nodulosities, forming a row coronating the whorl at the anterior edge of the 

 suture ; (2) thirteen or fourteen stoutish ribs, beginning in front of the anal 

 fasciole, extending over the periphery, under the spirals, bifurcating or even 

 trifurcating on the base, and becoming obsolete toward the canal; whorls 

 rounded, turrited by the fasciole; base rounded-conic; canal rather long, 

 sharply curved to the right, slightly funnel-shaped at its extremity ; sinus, in 

 the young, shallow ; in the adult, strongly marked, not deep, but roundly ex- 

 cavated in the thick varix, nearly closed by a parietal lump of callus and a 

 projection from the outer lip, which are rounded and smooth at first, but later 

 are transversely ridged or lirate ; aperture narrow, backed by a stout varix, 

 arched forward in the middle, behind which the shell is deeply indented ; outer 

 lip thin, standing out from the inner edge of the varix, transversely lirate ; 

 inner lip generally smooth, except for the parietal lump above mentioned, but, 

 when completely adult, furnished in the middle with two small oblique trans- 

 verse ridges, rather distant from each other, and from a series of eight or nine 

 close-set similar ridges on the columella extending nearly to the end of the 

 canal, recalling the ridges in the aperture of a Trivia ; these are very short and 

 do not coincide with the spiral sculpture. Max. Ion. of shell, 17.5 ; max. Ion, 

 of last whorl, 11.0 ; max. lat. of shell, 7.8 mm. 



Habitat. Station 36, Gulf of Mexico, in 84 fms. ; Station 65, off Havana, 

 in 127 fms. ; Station 132, in 115 fms., off Santa Cruz, on rocky bottom ; Station 

 147, off St. Kitts, in 250 fms., sand; Station 155, off Montserrat, in 88 fms. ; 

 Station 220, near Santa Lucia, in 116 fms., rocky bottom ; off Barbados, in 

 100 fms. ; at Stations 272 and 282, in 76-154 fms., coral ; and Station 296, in 

 84 fms., hard bottom. Also by the U. S. Fish Commission at Station 2405, 

 in the Gulf of Mexico, west of Florida, in 30-50 fms., sand and coral. 



This elegant species was submitted to Mr. Tryon when engaged upon his 

 monograph of the Pleurotomidce, and regarded by him as new. Though beauti- 

 fully fresh, not a single specimen came to hand with the soft parts included. 

 The surface is covered with a beautiful minute shagreening, which to be seen 

 requires a magnification of six or eight diameters. The figures do not show the 

 peculiar denticulation of the inside of the aperture. Most of the specimens 

 were without it, and the only adult specimen figured is turned so that the 

 outer lip would hide this peculiar feature. As the specimens for figuring were 

 selected long before they could be critically studied in some cases, it was im- 

 possible always to avoid such omissions. 



