DALL: MOLLUSCA and BRACHIOI'ODA. 401 



Both valves were originally covered with fine, concentric, umbonally inflected, 

 concrescent lamellae, which are usually entirely cleaned oflF in cabinet specimens. 



Chlamys Bolten. 



NODIPECTEN Ball. 

 Pecten (Nodipecten) subnodosus Sowerbt. 



Pecten subnodosus Sowcrby, P. Z. S. Lond., 1835, p. 109; Tlies. Conch., 1843, Pecten, 

 p. 66, pi. 15, figs. 97, 112. 



Gulf of Tebuantepec, in 10-17 fathoms, Sowerby ; U. S. S. "Albatross," 

 station 3368, near Cocos Island, in 66 fathoms, rocky bottom, temperature 

 58°.4 F. U. S. N. Mus. 122,863. Also Gulf of California. 



PALLIUM ScnuMACiiEH. 

 Pecten (Pallium) miser Dall, n. 8p. 



Plate 8, figrure 6. 



Shell small, flattish, dar k reddish purple, with a narrow hinge line, striated disk 

 and five strong radial ribs ; anterior ear very short, oblique ; posterior ear longer, 

 triangidar, with three radial threads near the hinge Hne, an excavated, concen- 

 trically striated space between them and the edge of the disk ; right valve with 

 five, strong, rounded ribs with subequal interspaces, and two much smaller, 

 closer, and less prominent, near the anterior submargin, and a single, similar riblet 

 near tbe posterior submargin; ctenolium rather long with about five free hooks'; 

 minor sculpture of the disk consisting of very numerous subequal radial threads 

 with subequal interspaces crossed by still more numerous fine, imbricated, sharp 

 lamellae which, when the surface is intact, coalesce, but when it is worn show as 

 sharp concentric lamellae looped over sharp radial ridges with distinctly wider 

 interspaces; distal margin of the valve suddenly and markedly contracted in the 

 adult ; hinge line with strong plicae on each side of tlie cartilage pit, strongly 

 vertically striated; interior smooth, ridged by the sculpture, livid purple with 

 strong lirations near the valve margin, on the lateral margins of each rib ; valve 

 margin minutely crenulate. Alt. 34.0; lat. of valve, 32.0 ; of binge margin, 9.0; 

 diameter of right valve, 6.0 mm. 



U. S. S. " Albatross," station 3355, Gulf of Panama, in 1S2 fathoms, mud, 

 bottom temperature 51°. 1 ¥. U. S. N. Mus. 122,862. 



Only two upper valves of this species were obtained, but as it belongs to a 

 group totally distinct from any other on the Pacific Coast, so far known, it can be 

 recognized without difiiculty. 



Pecten (Chalmys) pasca Dall, n. sp. 



Shell (left valve) flat, irregular distally, rose-pink and white, irregularly 

 clouded, somewhat inequilateral; anterior car larger, with four crimson radial 



VOL. XLIII. — NO. G 2(5 



