238 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
Trivia californiana Gray, 1828 
Zoological Journal, 3:365. 
Testa ovata, ventricosa, purpureo-fusca; striis longitudinalibus con- 
vexis, distantibus, apice sub-incrassatis; linea dorsali latiuscula, impressa, 
albida; basi planata, submarginata; apertura lineari; dentibus subequali- 
bus. (Gray.) 
Shell ovate, ventricose, purplish brown; the longitudinal striae are 
distant and convex; their ends are slightly thickened in the middle of the 
back, where there is a broad, whitish, impressed dorsal line. The base is 
rather flat, and slightly margined on the outer lip; the aperture is linear; 
the teeth of the inner lip 11, of the outer 16, nearly similar, small. Length, 
4.1; diameter, 3.1 in. (Gray.) 
Type in British Museum. Type locality, California. 
Range. Crescent City, California, to West Mexico. 
Trivia solandri Gray, 1837 
Conchological Illustrations ( Cypraea ), No. 128, fig. 43. 
Shell reddish brown, with a light-coloured dorsal groove, and a dark 
streak along each side of it; ribs prominent, wide apart, tuberculated at 
their dorsal extremities, mouth rather narrow, teeth of the outer lip more 
numerous than in C. radians; margin generally broad. Length, 0.7; 
breadth, 0.55 mm. (Gray.) 
This species is very much like radians , indeed it is impossible to know 
which of the two, this or the one we commonly call by that name, is the 
radians of Lamarck. The principal difference is in the number of teeth on 
the inner edge of the outer lip. (Gray.) 
Type in? Type locality? 
Range. Catalina Island, California, to Panama. 
Described as Cypraea. 
Trivia ritteri Raymond, 1903 
Nautilus, 17:85. 
Shell small, white, form ovate, inflated, anterior extremity slightly 
produced, spire completely covered, but rather prominent, base convex, 
outer lip margined, strongly sculptured with about twenty smooth, sharp 
ribs, much narrower than the interspaces, which are nearly flat and 
scarcely roughened by irregular rugae parallel to the axis of the shell; no 
sulcus, the ribs continuing unchanged in width across the back, except 
that occasionally a few ribs near the spire are interrupted at the median 
line; a few short intercalary ribs are usually present on the sides of the 
shell; aperture rather wide, armed with 17 to 18 denticulations on the outer 
[ 536 ] 
