CLASS PELECYPODA 
13 
Nucula carlottensis Dali, 1897. 
Plate 28, figs. 7, 8. 
Nat. History Soc. British Columbia Bull. No. 2:6; pi. 1, figs. 15, 16. 
Shell small, solid, yellowish olive color, moderately convex with in¬ 
conspicuous beaks; in perfect specimens the prodissoconch is rather large, 
smooth and white, but it is commonly eroded; the nepionic shell outside 
the limits of the prodissoconch is distinguished from the rest by having 
only delicate concentric sculpture, which abruptly changes to a stronger 
sculpture of somewhat irregularly concentric ridges with narrower inter¬ 
spaces crossed by numerous fine uniform striae; there is no well defined 
lunule or escutcheon; the margin in front of the beaks is marked by a 
radial impressed space, the margin enclosed by which is a little pouting; 
the interior of the shell is pearly, radially striate near the finely crenulate 
margin; the chondrophore is narrow and projects backward obliquely into 
the cavity of the valves; there are about eight anterior and twelve posterior 
teeth. Height of the shell, 5.2; length, 6; diameter, 3.5 mm. 
Type in U. S. N. M. Type locality, off Queen Charlotte Islands, in 
876 fathoms. 
Range. Queen Charlotte Islands, British Columbia, to Anacapa 
Island, California. 
Nucula exigua Sowerby, 1832. 
Proc. Zool. Soc., p. 198. Hanley, Mon. Nuculid<z; pi. 4, fig. 136. 
Nuc. testa parva, oblique ovata, albicante, pellucida, concentrice sul¬ 
cata ; latere postico longiore, subacuminato, antico brevissimo: long. 0.2, 
lat. 0.1, alt. 0.15 poll. (Sowerby.) 
Shell minute, short, elevated, subtrigonal, very minutely decussated; 
posterior side acuminated below; anterior side truncated. (Conch. Iconica.) 
Type in Mus. Cuming, British Museum. Type locality, West Colom¬ 
bia, Bay of Caracas. 
Range. Golden Gate, California, to Acapulco, Mexico. In the Plio¬ 
cene of San Pedro and San Diego, California. 
Nucula tenuis Montagu, 1808. 
Plate 5, fig. 12, and plate 37, fig. 4. 
Test. Brit. Suppi., p. 56. Hanley, Mon. Nuculidae, pi. 4, figs. 140, 141. 
Shell sub-cordate, smooth, white, covered with an olivaceous epider¬ 
mis ; umbo very small; beaks slightly inflected, and placed near the end. 
Inside smooth, white and somewhat nacred; margin thin and entire; hinge 
pectinated with about fifteen elevated teeth placed within the margin, six 
on one side and nine on the other, divided by a small concave plate that 
projects inward. Length 4-8; height, 4; diameter, 2 mm. (Montagu.) 
