i6 



It is not without some hesitation, that I have described this species as a Phenacolepas\ 

 it is much smoother than most of the described species, and has a conspicuous epidermis. 

 I know no species with which to compare it. As the soft parts wanted, I was not able to get 

 sufficient certainty. 



Pseudococculina n. g. 



Shell patelliform, white, with a posterior, inclined apex and a compressed, subspiral 

 nucleus. Inside porcellaneous, muscle-scar horseshoe-shaped, interrupted over the head. Animal 

 with a plumate gill, at the right side of the head; the right tentacle thickened; two epipodial 

 filaments at the posterior part of the foot. 



Radula with large rhachidian teeth, cusp wanting or very obsolete, first laterals triangular, 

 followed by 3 smaller, contorted laterals, with distinct cusps, a large cusped fifth lateral, and 

 numerous uncini. 



The radulae of the species described hereafter, seem to be different from those of similar 

 moUusks, however I think it is nearest allied to Phenacolepas^ by the shape of the first lateral ; 

 in other respects it differs sufficiently, to make it necessary to establish a new genus. The shells 

 resemble very much those of Cocculina^ the only difference, if it prooves to be constant, is that 

 no regular radial sculpture is to be found, as is the case in all the species of Cocciilina I have 

 examined. In the species described as Ps. rugosoplicata^ it is present in some degree, but of a 

 different character, consisting of coarse short striae, quite overwhelmed by the concentric sculpture. 



I. Pseudococculina rugosoplicata n. sp. PI. I, fig. 2; PL VIII, fig. 6. 



Stat. 221. 6°24'S., 124° 39' E. 2798 M. 4 Spec. 



Shell small, white, elevated, oval, thin, the margin rests entirely on a plane surface; 

 front slope the largest, convex, side slopes irregularly convex, being slightly compressed at some 

 distance from the apex, posterior slope slightly concave, apex blunt, placed at about "/g of 

 the total length ; the nucleus wanting, by a strong erosion of the apex. Sculpture consisting of 

 irregular concentric rugosities or wrinkles, generally more distant from each other towards the 

 apex, more crowded towards the margin, with a tendency to form lamellae; on some parts the 

 upper side of the rugosities has coarse, short, riblike radiant striae, wanting in other places, 

 perhaps by erosion. Inside smooth. 



Long. 6, lat. 47^, alt. 27,^ Mill. 



The characters of the shell, as well as the external characters of the animal, agreed 

 sufficiently with those of the genus Cocculina^ but the radula is quite different. 



The rhachidian tooth (R) is elongate with convex sides, it has no reflected cusp, the 

 upper margin being only irregularly waved, near the base an oval spot seems to be thickened, 

 the first lateral tooth (i) is triangular, also without distinct cusp, but with a reflected or thickened 

 upper margin, followed by three laterals (2, 3, 4), which are little different from each other, 

 with a winged body, having the appearance of being turned outwards, the cusp standing at the 

 distal side; their cusps are simple, the next lateral (5) has a quadrate body with a thickened stalk 



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