NO. 11 39. DEEP- WA TEE MOLL USCA VEEEILL AND B USH. 803 



CUSPIDARIA ARCTICA (M. Sars) Dall. 



(Platos LXX1, !ig. 1>; LXXIV, tiff. 7.) 



\</rra arctica SARS, G. O., Mollnsca Reg. An-ticn- N>rvegi;c, p. Xf>, pi. t>, figs. 5, 

 a-c, 1878. SMITH, E. A., Report Voy. Chctllvitf/er, Zool. Lamellibranchiata, 

 XIII, p. 35, 1885. 



Cuspidaria ardica DALL, Bull. Mus. Comp. /o<".l., XII, p. 294, 1886. 



Not Neccra arctica YERRILL, Amer. Journ. Science, VI, p. 440, 1873. 



A single imperfect valve from station 70, south of Halifax, Nova 

 Scotia, in 190 fathoms, is referred to this species. Though worn and 

 slightly broken, it agrees closely with Sars' figure, but it cannot be fully 

 grown, for it measures but 14 mm. in length and 11 mm. in height. 



CUSPIDARIA FORMOSA, new species. 

 (Plates LXXIV, fig. 6; LXXIX, fig. 3.) 



Shell short, high, and swollen. Umbos prominent; beaks incurved. 

 Anterior portion broadly rounded, a little produced at the end, with the 

 dorsal margin convex and a little excurved; the ventral margin is 

 broadly and evenly rounded; the rostrum is short, broad at base, much 

 tapered; the postero- dorsal margin is nearly straight at first, then 

 slightly concave and a little upturned. The exterior is covered with 

 uneven lines of growth between which the surface is microscopically 

 striated and more or less iridescent. The color of the single specimen 

 is pale pink, externally and internally. The right valve has a promi- 

 nent, triangular lateral tooth with its base prolonged parallel to the 

 margin of the shell ; it is separated by a decided notch from the cartilage- 

 plate, which is of moderate size, ovate, somewhat oblique, with its inner 

 edge rounded and prominent. 



Length, about 16 mm.; height, 13 mm.; breadth, 10 mm.; beak to end 

 of rostrum, about 9 mm.; beak to anterior end, 8 mm. 



A single, much broken, specimen (No. 78313), station 2706, N. hit. 41 

 28', W. long. 65 35', in 1,188 fathoms, 1886. 



CUSPIDARIA FRATERNA, new species. 

 (Plates LXXI, figs. 7, 8; LXXV, fig. 6.) 



Shell similar to Cuspidaria obex<( (Loven), moderately large, consider- 

 ably swollen, rather thick and firm. for the genus, with a moderately 

 long, tapered rostrum. The umbos are rather prominent and swollen, 

 with the strongly incurved beaks nearly in contact. The anterior end 

 is broadly rounded with a regularly curved, convex dorsal edge which 

 rises nearly to the height of the umbos; the ventral margin is a little 

 protuberant. The postero-dorsal line slopes with a slightly concave 

 outline to the end of the rostrum ; on the ventral margin there is a dis- 

 tinct incurvature corresponding to a wave-like depression on the surface, 



