112 Bulletin 5 383 



14. Pentagonal ossiculje of the trunk of Encrinus of authors, which in 

 outhne, may be compared to figs. 6i and 62, of plate 13, vol. 2, of Par- 

 kinson's Organic Remains, but their surfaces do not now exhibit any 

 sculpture. 



Many of these shells exhibit the most unequivocal evidences of having 

 been in a plastic state, at some period or other, since their deposition in 

 their present situations. The fine strite of a Productus lineolatus, are so 

 interlaced on the middle of a valve of one of our specimens, as at once to 

 convince every observer, of the shell having been thiis partially dissolved, 

 and when in this state, to have been gently rubbed by some other body, 

 in two directions proceeding obliquely to the same ppint, so as to throw 

 the striae in that part, entirely out of their proper longitudinal direction. 

 It is very common to find shells, unnaturally flattened or compressed in 

 various ways and degrees, often without any fracture in the shell or cast ; 

 a circumstance which certainly could never happen to the shell, unless 

 it was in a plastic state, or in a state of partial solution. 



16. A specimen of carbonate of lime, on its surface a mass of sub-parallel 

 tubes, connected by short lateral processes. The whole much resem- 

 bles, and is probably congeneric with the Erismatholithus tubiporites, 

 {catetiatus) of Martin's Petrif. Derbi. t. 42, fig. 2, but the connecting 

 processes of the tubes, are much shorter than they are represented in 

 that figure; but it corresponds much more exactly with the tubiporite, 

 figured by Parkinson in his Organic Remains, vol. 2, pi. i, f. i., and 

 may with great propriety, form a new genus, the type of which will be the 

 Tubipora Strues of Lin. 



The genus is probably allied to Favosites and Tubipora. 



17. Trilobus. The abdomen of a species of this singular genus, fre- 

 quently occurs in the sandetone of the Missouri ; near Engineer Canton- 

 ment they are very common. The largest was rather more than one inch 

 long, by about i 3-10 inches in breadth at base, but the more general 

 length is about three-fourths of an inch. The tergum or intermediate 

 lobe is narrow, being not more than two-thirds of the width of the flanks, 

 and much more convex than those parts. 



But a single specimen occurred which we can, without any doubt, con- 

 sider as the thorax of a Trilobus; but whether or not it appertains to the 

 same species with the above, or to some other of which we have no other 

 fragment, we are at a loss to determine. Like the abovementioned ab- 

 domen, it is distinct from any that we have seen figures of. It is of a nar- 

 row lunate form, highly convex, the disk destitute of sculpture, and the 

 eyes prominent. 



18. Many imperfect casts of two different kinds of bivalve shells occur 

 near Engineer Cantonment, of which one may possibly have been a Car- 

 dita. 



\^Foot note, page i4g\ . 



19. Tooth of a Squalus, which seems to approach nearest to those of 

 Sg. maxinius, by its compressed conic form. 



Greatest length 2 i-io inches. 

 Thickness more than 2-5 of an inch. 



The sides are rounded, without any appearance of serratures ; thicken- 

 ed near the tip, and more compressed near the base. 



20. Tooth of a Squalus, something like that of ►S". galeus, but less of a 

 triangular form, and the lateral processes are more distinct, and also less 

 triangular than in that species. 



[Long's Expedition to the Rocky Mountains, Vol. I, 1S23]. 



