38 CRYPTOPHTHALMUS. 
length of the animal, depressed, subcordate, triangular, convexly 
truncate in front, posteriorly separated by a fissure into two lobes, 
eyes deeply immersed in the cephalic disk, inconspicuous from 
above, their position being indicated by small pale spots, they can 
be distinctly seen by turning up the sides of the disk. The lateral 
lobes closely envelope the body, extending from the head to the ex- 
cretory tube, the left one overlapping the right; excretory tube at 
the posterior end of the body, short convolute. There is no groove 
between the lateral lobes and the locomotive disk. Color dusky 
olive, margins of the cephalic disk paler than centrally, and foot 
paler than above. When disturbed, the animal contracts itself as- 
suming a spherical form. Its motions are languid. Station on sea- 
weed in shallow water. (Pse.). 
Tahiti, on seaweed. 
Crypt. eylindricus Psx., P. Z. S. 1861, p. 245; Amer. Journ. 
Conch. iv, p. 74, pl. 7, fig. 7. 
Section PHANEROPHTHALMus Adams, 1850. 
Phanerophthalmus A. Av., Thes. Conch. ii, pp. 559, 599.—Xan- 
thonella Gray, Figs. Moll. Anim. iv, p. 95 (1850). 
Shell small, white, wholly buried in the mantle; entirely open, 
the spire indicated by an incurved hook on the middle of the left 
margin ; lip prolonged in a point above. 
Animal large, elongated, with foot as long as the body. Cephalic 
disk short, bearing distinct sessile eyes, bilobed behind ; parapodial 
processes large, reflexed and meeting over the back. Male orifice 
anterior, female posterior. 
The parapodial lobes are rather smaller than in Cryptophthalmus, 
and the eyes more posterior. 
C. LuTEUS Quoy & Gaimard. PI. 2, figs. 27, 28, 29, 30. 
Shell small, fragile, white, oval, open, not spiral; right margin 
sinuous and acute. 
Body much elongated, rounded; head shield emarginate in front, 
rounded at the sides, with two short posterior lobes; foot widened 
in front, then constricted, rounded behind; parapodial lobes long, 
curved over the back where they meet in a sinuous groove and a 
small hiatus behind. Eyes small, black, widely separated. Gill 
posterior, to the right, not visible externally. A groove joining 
the genital openings is on the same side. Shell contained within 
