160 NEW-YORK FAUNA — MOLLUSCA. 
SECTION 7. CIRROBRANCHIA. 
ANIMAL with its foot anterior and terminal, elongated into a conical shape, in order to penetrate 
sand. Gills in the form of numerous long filaments, arising from two radical lobes above 
the neck, and enveloped by the mantle, which opens in front: a few tentacular expansions. 
Eyes Sexes united. Suet simple, symmetrical, tubular. 
FAMILY DENTALID2. 
With the characters of the section. Only one family as yet observed. 
GENUS DENTALIUM. Luinneus. 
Animal with small oval distinct head. Mouth terminal, surrounded by digitated labial pro- 
cesses, furnished with a pair of lateral oval jaws bristled with points. The cylindrical 
mantle enveloping nearly the anterior half, terminating in front in a sort of collar, through 
which is apparent the circular opening of the foot. Foot ending in front in a sort of cup, 
in the centre of which is a conical appendix. Gills disposed in long filaments, arranged in 
two groups on each side of the upper part of the neck. Vent median, at the posterior ex- 
tremity. Generative organs unknown. Shell tubular, elongated, conical, not spiral, very 
slightly curved, open at both ends. 
Oss. Nearly fifty fossil and recent species of this genus are noticed in the most recent 
systematic works, of which one fossil species only is noticed from the United States. In the 
most recent edition of Lamarck’s Animaux sans vertébres, the animals of this genus are still 
arranged among the Anmelides. But one recent species has been observed on our coast. 
DeENTALIUM DENTALIS. 
PLATE X. FIG 197. 
Dentalium dentalis, Lin. Syst. Nat. 1263, 
D. id. GouLp, Invertebrata of Mass. p. 156, fig. 5, excl, syn. 
Description. ‘‘ Shell slender and tapering, shaped like an elephant’s tusk; the tip cut off, 
leaving a very small opening. Surface rather glossy, yellowish white, marked with about 
twenty closely arranged unequal rib-like strie, running the whole length of the shell. Length 
about an inch; diameter at the larger end about one-eighth of an inch.” 
Two specimens of this shell, according to Dr. Gould, whose description I have copied, 
were obtained from the stomachs of codfish on the coast of Massachusetts. 
