VO i«89."] PROCEEDINGS OF THK NATIONAL MUSEUM. 347 



The cephalic tentacles, for tho size of tlie animal, are small ami short. 

 At their inner bases are small " palmettes," or cephalic epipodial fringes, 

 not quite meeting in the middle line. They are rounded, with papillose 

 edges. At the outer bases of the tentacles are the eyes, large, oliviforin, 

 mounted on short pedicels. The pigmented portion itself is ovoid and 

 not hemispherical. In some specimens the pigment seems to be more 

 extensive on the under side, in others the reverse, and still others have 

 it equally distributed. A lens and aqueous humor are distinctly observ- 

 able. At the right side, behind and on a level with the eye, is a short 

 tubular verge. The anterior epipodial side lappet does not appear to 

 be modified into a seminal conduit, as in Margarita infundibulum Wat- 

 son. These lappets are nearly symmetrical. Their bases are turned 

 up a little on each side behind the eyes and the lappets are rather wide. 

 They extend backward about two-thirds of the way to the operculum, 

 with a finely papillose edge. Then comes a single tentacular filament, 

 less than half as long as a cephalic tentacle. There is another stretch 

 of edge fringed with only small papillae ; .under the operculum there are 

 three long filaments, of* which the posterior is longest. Behiud the 

 operculum the epipodial lines of the two sides approach each other and 

 bound a median furrow, coarsely transversely ridged (as in Pleuroto- 

 maria), which extends to the end of the foot. 



The mantle edge is smooth or very sparsely papillate, slightly thick- 

 ened. The free end of the intestine projects on the right side over the 

 neck, with its termination constricted by a sphincter, and then expanded 

 into a cup-shaped circular foramen. On the left side is the gill, consist- 

 ing of a central, somewhat muscular, ensiform basement, from which 

 depend two sets of elongate triangular lamellae, separated by a narrow 

 ridge. The left-hand set are slightly the longer. Most of the gill is 

 free. Its distal end is pointed and the lamellae hang side by side, with 

 the ridge between the two series, as in Nucula. The intestine takes a 

 curve to the left side, where the renal gland is visible between it and 

 the gill. I observed no osphradium. 



The mouth is small. A short distance behind it is a deep radular 

 diverticulum. The jaws are small, triangular, and dark brown. The 

 gullet opens almost directly into an elongate, large, longitudinally 

 wrinkled stomach. Behind it the very large intestine, with longitud- 

 inally striated walls, extends backward about half a whorl, then turns 

 upward and forward for a third of a whorl ; then back again upon itself 

 about the same-distance ; then forward to its anal termination, above 

 described. 



The liver and seminal gland appear to resemble those of ordinary 

 Trochids. 



The operculum is amber-colored, polished, thin, and centrally de- 

 pressed. It has about a dozen whorls. The opercular pad is ovoid 

 and rather small. 



The radula is quite small and the anterior part dark brown. The 



