CLASS GASTROPODA 
157 
distinct suture; axial sculpture of (on the last whorl, a dozen) rather 
narrow, nearly vertical ribs, which extend from suture to suture on the 
spire and from the suture to the margin of the base in the last whorl, with 
wider interspaces; incremental lines rather marked; spiral sculpture of 
(on the spire, four; on the last whorl, eight) prominent threads with 
wider interspaces, overriding the ribs and coming to a node when they 
intersect them; the base nearly smooth except for one or two minor threads 
near the canal; aperture semilunate, the outer lip thin, body with a thin 
layer of enamel; pillar with three oblique plaits, canal shallow, short, with 
a faint fasciole. Height of shell, 7; of last whorl, 5; diameter, 4.5 mm. 
(Dali.) 
Type in United States National Museum, No. 211241. Type locality, 
United States Bureau of Fisheries Station 4343, off South Coronado 
Island. 
Range. Santa Rosa Island, California, to S. Coronado Island. Also 
Pleistocene. 
Admete microsoma Dali, 1908 
Bulletin, Museum of Comparative Zoology, 43:296; PI. 11, fig. 10. 
Shell small, thin, covered with a pale-brownish periostracum, with 
about five tabulate whorls beside the (lost) nucleus; suture distinct, not 
channeled; whorl in front of it flattened, beyond the keel at the shoulder 
moderately rounded; axial sculpture of lines of growth which are at 
intervals so prominent as to suggest faint ribs; spiral sculpture compris¬ 
ing a marked keel at the shoulder, minutely undulate by the axial riblets, 
and followed by a wide interval; about eight less prominent spiral threads, 
separated by successively narrower intervals with microscopic intercalary 
threads, covering the whole base; aperture ovate, outer lip thin, simple, 
sharp; body smooth; pillar straight, short, thin, with two plaits, the 
anterior of which forms the edge of the columella; anterior part of aper¬ 
ture with a distinct, but not deep rounded notch. Long, of shell, 3.5; 
of last whorl, 2.5; of aperture, 1.7; max. diam., 1.8 mm. (Dali.) 
Type in United States National Museum. Type locality, Station 3418, 
off Acapulco, Mexico, in 660 fathoms. 
Range. North Coronado Island (656 fathoms) to Acapulco. 
Admete couthouyi Jay, 1839 
Plate 16, fig. 2 
Catalogue of Collections, 77. Boston Journal of Natural History, 2; PI. 3, fig. 3. 
Shell ovate-conical, somewhat turreted, milky-white, approaching to 
horn-color; whorls five or six, convex, flattened at the top; suture well- 
[1571 
