STANTON.] FUSID.i:. 151 



Trackytriton; but although the vertical folds are distinctly marked 

 where the shell is entirely removed, there is no evidence of revolving 

 lines on the spaces between them, as required in the diagnosis of that 

 genus. 



U Formation and locality, — In a ferruginous sandy limestone on the 

 east fork of Beaver creek, Black hills, associated with fossils referred to 

 the Fort Benton group." 



This species seems to have been abandoned by Prof. Meek, as he does 

 not include it in his final work on the "Invertebrate Cretaceous and 

 Tertiary Fossils of the Upper Missouri Country," and he there speaks 

 of it as a possible synonym of Trachytriton vinculum. The original 

 type was found in the Fort Pierre group at the Great Bend of the Mis- 

 souri. It is somewhat doubtful whether the specimen above described 

 belongs to the same species. (See remarks on Pleurotoma hitzlj p. 161.) 



Fusus gabbi Meek. 



PI. xxxi, Fig. 14. 



Fusus (Neptunea) gaUi Meek, 1873, Ann. Rept. U. S. Geol. Sur. Terr, for 1872, p. 504 j 

 White, 1879, idem for 1877, p. 317, PI. 9, Fig. 9a. 



Original description : 



"Shell rather small, fusiform; spire moderately prominent, conical; 

 volutions seven or eight, convex; last one somewhat ventricose in the 

 middle, and rather suddenly contracted below into the narrow, slightly 

 twisted, more or less bent, and apparently moderately produced canal ; 

 suture well defined ; aperture rhombic-subovate, and rather suddenly 

 narrowed into the canal below. Surface ornamented with equal, dis- 

 tinct, regularly disposed varices or vertical folds, about eight of which 

 may be counted on the penultimate volution, and less on the body- whorl, 

 where some of them become obsolete; crossing these are also seen fine 

 revolving lines, and a little below the suture, apparently a shallow 

 revolving furrow that gives it a slightly banded appearance. 



"Length, including canal, about 0.87 inch; breadth, 0.40 inch ; slopes 

 of spire straight, and diverging at an angle of about 50°. 



"The specimens of this species contained in the collection are quite 

 imperfect, being mainly casts retaining more or less of the shell. From 

 such material it is, of course, impossible to determine with much con- 

 fidence the generic affinities of shells. I have, therefore, provisionally 

 referred it to the genus Fusus, putting in parenthesis the name Nep~ 

 tunea with a mark of doubt, to indicate that I suspect it may belong to 

 that group, with the limits assigned it by some conchologists. It 

 seems, however, quite as probable to belong to Tritonidea, as under- 

 stood by some. 



" Locality and position. — Coalville, Utah; from the Cretaceous beds 

 below the lower heavy bed of coal mined at that place.' 7 



