fi4 



obliquely compressed at the sides; l)raohial or hremal valve mucli the 

 flattest of the two. The beaks are partly broken in each specimen, but 

 the foramen was undoubtedly large : the size and shape of the deltidium 

 cannot be ascertained: Front of the valves almost straight, or, at any 

 rate, not distinctly sinuous. 



The test is exfoliated in every case, but there is clear evidence that 

 the surface was marked with rather distant concentric striro, and in one 

 specimen at least with fine and close set radiating lines. The jnnictate 

 character of the shell is also plainly visible with a lens. Length of the 

 largest example, two inches and two lines ; width, twenty-three lines ; 

 maximum convexitj' twelve and a half lines. 



The species is repi-esented by three bi'oken and badl}" preserved 

 specimens, which have very much the aspect of T. depressa, Lamarck, 

 and T. suhdepressa, Stoliczka, as represented in the " PahTontologia 

 Indica,"* but they are too imperfect to be identitied with much cer- 

 tainty. 



Terebratula (?) (8p. Undt.) 



A small specimen of possibl}^ another species of Terebratula, but in 

 very bad condition, and parti}" buried in the matrix. It has a moi-e 

 convex h(vmal valve than the shell last described, and a much smaller 

 foramen. 



AI^THOZOA. 



The only coral collected is so much water worn that its generic 

 position is doubtful. 



ADDITIONS AND CORRECTIONS. 



Nautilus, Sp. Undt. (raf,a's 14-19.) 



The remarks under tliis heading were written in 1875, hefore the publication of the 

 " Report on the Invertebrate Cretaceous and Tertiary Fossils of the Upper Missouri 

 Country." In that very useful work, Mr. Meek expresses an opinion that the NmUilus 

 elegans of Sharpe is probably identical with N. elegans of Sowerby, but that N. elegans, 

 D'Orbigny, is perhaps distinct. With all due deference to Mr. Meek's judgment, the 

 writer can scarcely see his way clear to accept the first of these conclusions. Sharpe 's 

 description and figures of N. elegans do not accord at all well with those of the type 

 in the " Mineral Conchology," yet no reasons are given to account for a discrepancy 

 which, it is thought, must have been obvious if the two forms had been compared 

 directly. 



' Vol. IV. pp 16, 17. Plate II., and Plate III., figs. 1-8, 



