Bulletin 5 288 



40 Say on Shells, &c. 



fatiscent. Amongst these I recognized a Crepidula, which 

 differs from any I have seen, but is too imperfect to be de- 

 scribed. A portion of an obtusely rugose incrassated, Se7'- 

 pula. A Peden which does not appear to have attained to 

 its complete growth. A small laminated Cyiherea, Lam. 

 a Fisstirella allied to F. groeca, but immature. A Turri- 

 tella, and fragments of a Balantis of considerable size, seve- 

 ral specimens of a Nucula and of a Calyptroea. The two 

 latter may be described as follows. 



Nucula obliqua, valves obliquely subtriangular, obsoletely 

 striate transversely, one or two of the striae more conspicu- 

 ous, numerous, hardly perceptible longitudinal striae ; ante- 

 rior and posterior sides forming an acute angle ; tunbo ob- 

 tuse ; apex acute ; teeth angulated, prominent, cavity at the 

 apex of the hinge profound, rather long ; basal margin den- 

 ticulatocrenate. 



Greatest length one fifth of an inch. — 



Very much resembles Area nucleus Lin. but is a smaller 

 species, and proportionally narrower towards the apex, the 

 hinge teeth are also more prominent and the cavity at the 

 apex of the hinge is proportionally larger. 



Calyptroea costata, oval, convex, with numerous slightly 

 elevated, equal equidistant costae, and crowded obtuse, con- 

 centric lines, which are regularly undulated by the costae ; 

 apex mamillated inclining to one side ; inrier valve pate- 

 liform, dilated, attached by one side to the side of the shell, 

 acutely angulated at the anterior junction, and rounded at 

 the posterior junction, and rapidly tapering to an acute tip, 

 which corresponds with the inner apex of the shell. 



Length nearly one inch — 



Seems to approach, in its characters to the genus I7if2indib- 

 ulum. of Montf. but from the fatiscent state of the specimens, 

 this cannot be acurately determined. No definite spiral su- 

 ture is perceptible. , 



Genus Baculites, Lam. 



Shells straight, cylindrical, compressed, slightly conic, 

 divided within into transverse septa, which are sinuous or 

 ramose on their margins and pierced with a siphunculus ; 

 siphunculus at one extremity of the longest transverse di- 

 ameter. 



[A. J. S., ist Sen, Vol. II.] 



