DALL: MOLLUSCA AND BRACHIOPODA. 403 
small, polished prodissoconch) small, pointed, the left one rising a little higher 
than the other; hinge line straight, ears subequal, sharply pointed, byssal notch 
and fasciole distinct, sculpture like that of the disk; surface of the valves with 
about four easy, wide, rounded undulations; surface sculptured with numercus 
fine, squarish, radial and concentric threads subequal and subequally distributed, 
so that the meshes are mostly square, without nodulation at the intersections, 
and the interspaces are wider than the threads; disk short, kite-shaped, a little 
produced in front, suddenly constricted at the margin; interior white, polished, 
the umbonal cavities extending under the hinge line; the pit and resilium small. 
Alt. 12.0; lat. of shell, 12.0; of hinge line, 7.7; diam. 4.0 mm, 
U.S. 5. “ Albatross,” station 4721, Pacific Ocean in South Lat. 8° 7’, and 
West Lon. 104° 10’, in 2084 fathoms, globigerina ooze, bottom temperature about 
35° F. U.S. N. Mus. 110,579. 
This is a most exquisite little gem of the sea. 
Pecten (Pseudamusium) polyleptus Da zt, n. sp. 
Plate 10, figure 9. 
Shell small, thin, translucent white, compressed, having a marked “ Cump- 
tonectes” striation, beside about thirty-six radial rows of minute, elevated, granule- 
like scales, very easily detached and more crowded near the middle of the base; 
hinge line straight; anterior ear in the right valve long, prominent, with five 
radial rows of scales and obvious concentric striation ; byssal notch deep and 
wide, with a broad fasciole, the ctenolium with three free teeth ; posterior ear not 
differentiated by a notch; profile of the valve, below and behind, a segment of 
a circle ; interior with glassy polish, scar small and high up, hardly visible; mar- 
gins entire; ligamentary pit small, shallow. Alt. of valve, 9.5; lon. of valve, 9.5 ; 
of hinge line, 6.5; diam. of right valve, 1.2 mm. 
U.S. 58. “ Albatross,” station 4642, Galapagos Islands, four miles S., 41° E., 
from Ripple Point, Hood Island, in 300 fathoms, globigerina sand, bottom tem- 
perature 48°.6 F. U.S. N. Mus. 110,586. 
Only the right valve was obtained at this station, but at station 2781, on the 
west coast of Patagonia, Southern Chile, in South Lat. 51° 52’, in 348 fathoms, 
mud, bottom temperature 50° F., a left valve which probably belongs to the 
same species was dredged by the “‘ Albatross” in 1888. The sculpture is essen- 
tially similar, except that the scales are fewer and more distant from each other ; 
only 34 rows could be counted, and the umbonal part of the valve shows several 
concentric undulations. The ears are large, subequal, the anterior larger with six 
radial rows of scales. The ‘‘ Camptonectes”’ sculpture is conspicuous upon the 
glassy shell. 
Pecten (Pseudamusium) gelatinosus MasiLie et RocHEBRUNE. 
Pseudamusium gelatinosum M. et R., Miss. Cap Horn, Moll., 1889, 6, p. H 126. 
Orange Harbor, Mabille; U.S. 8. “ Albatross,” station 2785, in 449 fathoms, 
mud, temperature 47° F. U.S. N. Mus. 96,454. 
