CLASS PELECYPODA 
41 
Type in U. S. N. M., No. 122929. Type locality, U. S. S. Albatross 
station, 3418, off the Mexican coast, in 660 fathoms. 
Range. San Diego, California, to Acapulco, Mexico, in deep water. 
Tindaria kennerlyi Dali, 1897. 
Plate 1, fig. 6. 
Nat. Hist. Soc. Brit. Col. Bull. No. 2:11; plate 2, fig. 9. 
Shell small, cythereiform, plump, with a yellowish periostracum; 
beaks full, rather prominent; valves nearly equilateral, rounded before and 
behind, base regularly arcuate; surface uniformly sculptured with rounded 
narrow, equal close-set small concentric riblets; lunule and escutcheon 
obscure or none; interior white, the pallial line hardly sinuate; ligament 
short, external, opisthodetic; hinge plate and teeth rather strong, anterior 
teeth about 12, posterior 14, the series hardly interrupted. Length, 6.5 ; 
height, 5 ; diameter, 4 mm. (Dali.) 
Type in U. S. N. M. Type locality, off coast of Washington. 
Range. Off Sitka, Alaska, to the Santa Barbara Islands, in deep 
water. 
Family ARCIDZE. 
Genus GLYCYMERIS Da Costa, 1778. 
Shell orbicular, nearly equilateral, smooth or radiately striated; 
umbones central, divided by a striated ligamental area; hinge with a semi¬ 
circular row of transverse teeth; adductors sub-equal; pallial line simple; 
margins crenated inside. (Tryon. S. S. Conch.) 
Type. Area glycymeris (Linn). 
Distribution. West Indies, Britain, India, New Zealand, West 
America. 
Glycymeris septentrionalis Middendorff 
Mai. Rossica, 3:67; plate 21, figs. 1-3. 
Shell of medium size, nearly circular, convex, thick; umbones central, 
not prominent; surface sculptured with rather faint ridges of growth and 
radiating grooves, which are more or less interrupted by the ridges; tri¬ 
angular ligamental area between umbones divaricately striated; hinge with 
a semi-circular row of transverse teeth; muscle impressions subequal; 
interior of margin crenulated. Length, 30; height, 32.2; diameter, 22 mm. 
(Arnold.) 
Type in Academy of St. Petersburg. Type locality, Arctic. 
Range. Aleutian Islands to Puget Sound. In the Pleistocene at San 
Pedro, California. 
