Page:American Seashells (1954).djvu/505

Rh Genus Chione Miihlfeld 1811 Shells trigonal or ovate; thick; 3 cardinal teeth in each valve; no anterior laterals; pallial sinus small and triangular; inner margins crenulated; lunule bounded by an indented line; escutcheon smooth and bounded by a small ridge. Subgenus Chione s. str. Chiojie cancellata Linne Cross-barred Venus Plate 39h North Carolina to Florida, Texas and the West Indies. I to I % inches in length, varying from ovate to subtriangular in shape, thick; with strong, raised, curved, leaf-like, concentric ribs and numerous coarse radial ribs. Escutcheon long, smooth and V-shaped, commonly with 6 to 7 brown, zebra-stripes. Lunule heart-shaped, with minute vertical threads. Color externally is white to gray; internally glossy-white with a suffusion of purplish blue. A very common, shallow-water species in Florida. Beachworn specimens have a cancellate sculpturing. The subspecies mazycki Dall, off the Carolinas, Georgia and northeast Florida has a beautiful rosy interior. Chione intapurpurea Conrad Lady-in-waiting Venus Plate 39g North Carolina, the Gulf States to the West Indies. 1 to I ^ inches both ways, thick, glossy-white to cream; interior white, commonly with a violet, radial band or splotch at the posterior third. Ex- terior with crowded, smooth, low, rounded, concentric ribs. The lower edge of these ribs bears many small bars which are Imed up one below the other to give the shell the impression that it has axial ribs. The concentric ribs become sharp and higher at the shell's extreme ends. Lunule with raised lamellations; escutcheon with very fine, transverse lines. Uncommon. Incorrectly spelled interpurpurea. Chione califomiensis Broderip Common Californian Venus Plate 31) San Pedro to northern South America. 2 to 2 % inches high, a little longer, subtrigonal, moderately compressed, with sharp, raised, concentric ribs whose edges turn upwards, and with low, rather wide, rounded, radial riblets. Lunule heart-shaped and striated; es- cutcheon V-shaped in cross-section, long and smooth. The dorsal posterior end of the right valve is not as smooth and overlaps the left valve. Exterior