154 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
Type locality, Australia. 
Range. San Pedro, California, to the Gulf of California. Pleistocene, 
Santa Barbara to San Diego, California. 
Chione undatella Sowerby, 1853. 
Plate 55, fig. 2. 
Proc. Zool. Soc., p. 22. Thes. Conch., Venus, pi. 153, fig. 22. 
V. testa rotundato-elliptica, crassa, albida, fusca maculata, punctata, 
et undatim picta; costellis radiantibus cinfertis, aliisque decussantibus, 
undulatis, sublamellosis; latere antico breviore, postico subdeclivi; mar- 
ginibus depressis; margine ventrali rotundato, intus crenulato. Long. 1.6; 
lat. 1; alt. 1.5 poll. (Sowerby.) 
Shell ovate, rather -compressed, bluish white, lineally waved and 
blotched with violet brown, radiately regularly ridged, ridges obsolete 
toward the margin, concentrically ridged, ridges waved, close-set and 
strongly toward the margin, ligamentary area rather broadly excavated, 
conspicuously striped. (Conch. Iconica.) 
Type in Museum Cuming. Type locality, Gulf of California. 
Range. San Pedro, California, to Guayaquil. 
Chione succincta Valenciennes, 1832. 
Humboldt and Bonpland, Obs. Zool., p. 219; pi. 48; figs. 1, a-c. 
Shell of medium size, thick, subcordiform; surface ornamented by 
several about equidistant slightly reflexed, low concentric frills and nu¬ 
merous rounded, radiating ridges, most prominent on the middle of the 
shell, which increase by intercalation and become flattened and less 
prominent as the periphery is approached; lunule prominent, ornamented 
by both incremental laminae and rounded, radiating ridges; hinge narrow; 
two prominent cardinal teeth in each valve; pallial sinus very shallow; 
margin crenulated. Length, 55; height, 50; diameter, 32. (Arnold.) 
Type locality, not known to the writer. 
Range. San Pedro, California, to Panama. In the Pleistocene at 
Santa Barbara, San Pedro, and San Diego; in the Pliocene at Seven Mile 
Beach, San Mateo County, and San Fernando, California; in the Miocene 
in Oregon, and at Martinez, San Pablo, Griswold’s in San Benito County, 
Foxen’s in Santa Barbara County, and Santa Monica, California. 
Genus VENUS (Linnaeus) Lamarck, 1799. 
Shell thick, ovate, smooth, sulcated or cancellated; margins minutely 
crenulated; cardinal teeth 3—3; pallial sinus small, angular; ligament 
prominent; lunule distinct. (Tryon. S. S. Conch.) 
Type. Venus mercenaria Linn. 
Distribution. World-wide. 
Range in Time. Oolite, Pleistocene. 
