251 



OxYTOJiA MUCRONATA, Meek and Hayden. 



Plate 33, figs. 6, 6a, and 66. 



South side of Maud Island ; several good specimens of both valves. 

 For critical comments on the characters of this species, with reference 

 to the publications in which it is described, see page 238, ante. 



liuiA. (Species undeterminable.) 



South side of Maud Island : three casts of the left valve of a small, 

 obliquely and narrowly subovate, ribbed species of Lima. 



The shell appears to have been rather strongly convex, the front 

 margin is subangiilar in the middle in one of the specimens and the 

 ears are small. The surface of the central area of the cast is marked 

 by ten radiating ribs, with indications of a minute secondary rib 

 intercalated between each pair of the larger ones, but the outer por- 

 tions of the anterior and posterior sides are smooth. 



Pegten Carlottensis. (N. Sp.) 



Plate 33, fig. 7. 



Shell compressed, thin, and ovately orbicular, a little higher than 

 long, margin of the valves rounded at and below the middle, narrowing 

 abruptly, obliquely and somewhat concavely under the ears above : 

 shape of the ears not very perfeetl}' known : those of the right valve 

 appear to be small, and unequal in size, the right being rather the larger 

 of the two, triangular, straight above and truncated almost at a right 

 angle at the sides. 



Sui-face marked by about thirty very tlat radiating i-ibs of unequal 

 breadth, which are crossed by minute, exceedingly numerous and 

 densely crowded raised lines, or narrow and acute ridges. The radiat- 

 ing ribs, are nearly obsolete in the umbonal region, but are strongly 

 marked on the lower half of the valves, and ai'C separated by narrow 

 and not very deep grooves. 



Dimensions of one of the most perfect specimens (the one figured) : 

 length, eighteen millimetres : height, twenty. 



South side of Maud Island : apparently abundant, but the specimens 

 although well preserved are most of them very fragmentary. 



