CLASS PELECYPODA 
87 
ornata; epidermide tenui, pallide olivacea induta; parte postica truncata, 
parum hiante; antica valde rotundata; marginibus dorsalibus et ventali 
parum excurvatis; umbonibus angustissimis; regionibus lunulari et nym- 
phali subcarinetis; intus, margine cardinali utriusque valvae acuto; liga- 
mento inconspicuo; cartilagine subspongiosa, satis elongata, postice de- 
flecta; fovea haud indentata; cicatricibus adductorum parvis, subrotun- 
datis; sinu pallii majore, ovali, ad dimidium interapatii porrecto. Long., 
38; lat., 26; alt., 14; poll. (Carpenter.) 
Type in U. S. N. M. Type locality, Cape San Lucas, Lower California. 
Range. San Pedro, California, to Cape San Lucas, Lower California. 
Family PANDORIDiE. 
Genus PANDORA Bruguiere, 1792. 
Shell inequivalve, thin, pearly inside; valves close, attenuated behind; 
right valve flat, with a diverging ridge and cartilage furrows; left valve 
convex, with two diverging grooves at the hinge; usually no ossicle; pallial 
line slightly sinuated. Outer layer of regular vertical, prismatic cells. 
Type. Tellina inaquivalvis, Linne. 
Distribution. United States, Spitzbergen, Jersey, Canaries, India, 
New Zealand, Philippines, Panama. 
Subgenus Kennerlyia Carpenter, 1864. 
Pandora grandis Dali, 1877. 
Plate 15, fig. 10. 
Proc . Cal. Acad. Sci., 7:11. Publ. Puget Sound Biol. Station, 4; pi. 4, fig. 3, 1924. 
Shell large, plano-convex, not rostrate, dorsal margin of the convex 
valve angulated with reference to the longitudinal axis of the shell, as 
well as bent over the umbo of the flat valve so as to completely overshadow 
it. Convex valve externally smooth except for lines of growth, chalky, 
somewhat twisted. From the umbo an incised line passes to the ventral 
margin where it ends; the portion of the ventral margin behind the point 
marked by the end of this line extends ventrally some distance beyond 
the limit reached by that portion anterior to it. The anterior portion is 
equal to the flat valve so much that in life it appears as if part of the 
anterior ventral margin had been broken or cut out. The outer surface 
of the anterior area bounded by the incised line has also its lines of 
growth more regularly distributed, giving the appearance of light concen¬ 
tric sculpture, and usually retains the epidermis longer than the remainder 
of the valve, which is more convex. The interior of this valve is livid 
pearly, sparsely punctuate, and with the spectral grooves radiating from 
the hinge teeth. These are so faint that they can be seen in some lights, 
