IO ~ 
Measurement :—Anterior to posterior, 30; umbones_ to 
ventral margin, 23; thickness (valves united), 14 millim. 
Hab. :—Cape Infanta, N.E. by N. 4 N., 133 miles; 43 
fathoms. Bottom, coarse sand, etc. (one specimen). 
CRASSATELLA ABRUPTA, n.sp. (Plate VI., fig. 15). Shell 
short, subquadrate, somewhat inflated, very densely sculptured 
with fine raised granular radiating striz, and concentric 
regular lire; liree somewhat flattened, rather narrower than 
the interstices, becoming obsolete on the posterior side. Pos- 
terior dorsal margin rather convexly sloping, anterior rather 
concavely truncate ; posterior lateral margin nearly vertical,_ 
slightly convex, anterior rather prominent in the middle ; 
ventral margin roundly arcuate. Umbones small, shghtly in- 
curved anteriorly inclined ; cardinal area on both sides con- 
cave, posterior rather narrow, anterior rather broad. Interior 
whitish, posterior area suffused with pink, minutely crenulated 
within the margin; abductor scars and pallial line as in the 
preceding species. Hinge with two oblong anterior cardinal 
teeth, which are strongly crenulated at the sides, and a long 
very narrow posterior one ; anterior lateral with three long 
thin lamin, the inner one forming a very slightly pro- 
minent tooth ; posterior lamin nearly straight and smooth. 
Measurement.—Anterior to posterior, 16; umbones to 
ventral margin, 14; thickness (valves united), to millim. 
Hab. :—Umhloti River Mouth, N.W. 4 W., 153 miles; 
depth, 100 fathoms. Bottom, hard ground. 
This shell has very much the external appearance of an 
A starte. 
CRASSATELLA TENUIS, n. sp. (Plate VI., fig. 17). Shell trans- 
versely oblong, thin, compressed, pallid, angular behind, 
rounded in front; surface sculptured with fine radiating 
thread-like striz, and very close exceedingly fine concentric. 
strie ; concentric lire thin, erect, rather distant ; posterior 
dorsal margin straight, nearly horizontal, obtusely angled ; 
anterior obliquely sloping, very slightly concave ; posterior 
lateral margin nearly straight, slightly oblique; anterior 
rounded ; ventral margin long, rather straightly convex. 
Umbones minute, very slightly incurved; cardinal area 
impressed, long, moderately wide, anterior rather deep. 
Measurement :—Anterior to posterior, 26; umbones_ to 
ventral margin, 18; thickness (valves united), 8} millim. 
Hab. :—Cape St. Blaize, N. by E. } E., 65 miles; depth, 
90 fathoms (one specimen only). 
A very light compressed shell, somewhat resembling C. 
subquadrata, Sowerby. 
