636 ' REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



outer surface, which expands into a thin membrane toward the end. 

 Tentacular arms long and slender, in extension longer than the body, 

 the portion that bears suckers forming about one-third the whole 

 length ; in the female the larger suckers on the middle of this portion 

 are not so large as the largest on the other arms, and are arranged in 

 about four rows; those near the tips of the arms are very small and 

 crowded. In the male the principal suckers of the tentacular arms are 

 very much larger than in the female, and considerably exceed those of 

 the other arms ; they form two alternating rows along the middle of the 

 arm, and external to them there is a row of smaller suckers on each side, 

 alternating with them; the suckers toward the tips are very numerous, 

 small, and crowded ; outside of the suckers, on each side, there is a mar- 

 ginal membrane with a scolloped edge; another membranous fold runs 

 along the outer surface and expands into a broad membrane near the 

 end ; the arms of the ventral pair are intermediate in length between 

 those of the second and third pairs. Ground-color of body, head, arms, 

 and fins pale, translucent, yellowish white ; entire ventral surface pale, 

 with small, distant, brownish circular spots, which are nearly obsolete on 

 the siphon and arms ; the upper surface is covered with pale brown, 

 unequal, circular spots which are not crowded, having spaces of whitish 

 between them ; the spots are more sparse on the head and arms, but 

 somewhat clustered above the eyes. The general appearance of the 

 animal when fresh is unusually pale and gelatinous. The "pen" is 

 broad, quill-shaped, translucent, and amber-colored. A medium-sized 

 male specimen preserved in alcohol measures 145 mm from the base of the 

 dorsal arms to the posterior end of the body ; length of body,. 120 mm ; 

 length of caudal fin, 70 mm ; breadth of fin, 75 mm ; length of first pair of 

 arms, 42 mm ; of second pair, 50 mm ; of third, 60 mm ; of tentacular arms, 

 150mm . f ventral pair, 53 mm . 

 Long Island Sound. 



The Spirilla Peronii Lamarck, (Spirulafragilis in Binney's Gould, p. 

 516, fig. 755), is occasionally cast up, on the outer beaches of Nantucket, 

 but it probably does not occur alive in our waters. 



GASTEOPODA. 



PECTINIBRANCHIATA. 



Bela harpularia Adams. Plate XXI, fig. 108. (p. 508.) 



H. and A. Adams, Genera of Recent Mollusca, vol. i, p. 92, 1858 ; Gould's Inverte- 

 brata of Mass., ed. ii, p. 352, fig. 191. Fusvs harpuJarins Conthouy, Boston 

 Journal Natural History, vol. ii, p. 106, PI. 1, fig. 10, 1838 ; Gould's Inverte- 

 brata of Mass., ed. i, p. 291, fig. 191, 1841. Mangelia harpularia Stimpsou, Shells 

 of New England, page 48, 1851. 



Massachusetts Bay to Labrador and Greenland. Off Gay Head, 10 

 to 19 fathoms ; in the Bay of Fundy frequent in from 1 to 80 fathoms. 

 Fossil in the Post-Pliocene "Leda-clays" of Labrador (Packard); and 

 Canada (Dawson). 



