NO. 1139. DEEP-WATER MOLLUSCA VERRILL AND BUSH. ?[)9 



CUSPIDARIA LAMELLOSA (M. Sars) Dall. 



(Plate LXXIV, fig. 10.) 



Neasra lamellosa VERRILL, Trans. Conn. Acad., V, p. 561, 1882; VI, p. 277, pi. xxx, 

 fig. 3, 1884; Expl. Albatross, Report U. S. Com. Fish and Fisheries for 1883, 

 p. 574, 1885. 



Cuspidaria lamellosa DALL, Bull. Mus. Comp. Zool., XII, p. 294, 1886; Bull. U.S. 

 Nat. Mus., No. 37, p. 66, pi. XLV, fig. 3, 1889. 



Comparatively few specimens, at twelve stations, between N. lat. 40 

 2' 49", W. long. 68 49', and N. lat. 37 59' 30", W. long. 73 48' 40", 

 in 319 to 555 fathoms, 1880-1886. 



A few specimens occurred which differ from the typical form in hav- 

 ing hut five or six concentric lainelhe visible on the antero-ventral 

 portion of each valve and only conspicuous unequal lines of growth on 

 the rest of the surface. 



CUSPIDARIA TURGIDA, new species. 

 (Plates LXXII, fig. 7; LXXVII, fig. 4.) 



Shell rather large, thin, delicate, translucent, of a pinkish white 

 color within, long-oval, with prominent, posteriorly directed umbos, and 

 narrow, rather long posterior rostrum. The beaks are central, rather 

 acute and turned distinctly forward. The antero-dorsal margin is 

 slightly convex, forming a broad curve; the anterior end is a little 

 prolonged in the middle but otherwise pretty evenly rounded; the 

 ventral margin forms a regular, broad curve becoming strongly incurved 

 at the base of the rostrum; the postero-dorsal margin is straight at 

 first, but slightly concave along the rostrum. The cartilage-plate is 

 small and very oblique, and in the right valve, is separated by a dis- 

 tinct notch from the lateral tooth, which is long and low, with a 

 rounded summit and a long, gradual, posterior slope; there is no trace 

 of buttress or clavicle. In the left valve the hinge-margin is thin, and 

 nearly simple both anteriorly and posteriorly. The exterior surface is 

 covered with a thin, yellowish gray epidermis and is marked with 

 irregular, rather conspicuous lines of growth; on the rostrum there is a 

 distinct diagonal ridge running from the beaks to the lower margin. 



-Length, 22 mm.; height, 12 mm.; breadth, 11 mm.; distance from cen- 

 ter of beak to end of rostrum, 12 mm. ; to extreme anterior end, 12 mm. 



In form, general appearance, and length of rostrum, this species is 

 intermediate between C. glacial is and C. rostrata, but the umbos are 

 more oblique and there are obvious differences in the hinge. 



One live specimen (No. 78789), station 2714, N. lat. 38 22', W. long. 

 70 17' 30", in 1,825 fathoms, 1886. 



