WHiTK.] PALEONTOLOGY — CRETACEOUS FOSSILS. 305 



Genus ACTiEONINA d'Orbigny. 



ACT^ONINA PROSOCHEILA (sp. nOV.). 

 Plate 7, figs. 10 a and 6. 



Shell small, miicli involute, narrow, subterete, widest in front of the 

 middle; spire very small and short; volutions four or five, flattened on 

 the sides, which flattening is especially observable upon the last volu- 

 tion, the greater part of each of the others being successively covered 

 by partial involution; sutiu'e distinct, not impressed upon its distal side, 

 but the distal side of the volutions bend abruptly into the sutiu-e, giving 

 that side of the volutions a shouldered aj^pearance ; aperture moderately 

 large; distal portion very narrow; proximal portion moderately ex- 

 panded, and its margin rounded from the outer border to the end of the 

 columella, with which it forms an obtuse subangle; outer lip thin; inner 

 lip flexous, somewhat thickened, especially along its proximal portion, 

 where the flexure occurs. 



The only example discovered is a cast from which the test has been 

 almost wholly removed, but there are upon it indications that revolving 

 lines thickly covered the whole surface. They are apparently somewhat 

 coarser than those of the preceding species, Actceon looosteri, but noth- 

 ing further concerning their character can be ascertained. 



Length, 4^milUmeters; breadth at widest part, 6 J milMmeters; length 

 of aperture, 10^ millimeters ; length of spire beyond the distal end of the 

 aperture, nearly 4 millimeters. 



This species seems to be a true Actceonina. In general aspect and 

 surface-marking it resembles Actceon attenuata Meek & Hayden, which, 

 as suggested by Mr. Meek, may be an Actceonina, but it differs conspic- 

 uously in its much shorter spne and more slender general form. 



Position and locality. — Fox Hills Group; at the confluence of the Saint 

 Trains and South Platte Elvers, Northern Colorado, where it was dis- 

 covered by Mr. W. H. Holmes, artist and geologist of the Survey. 



Genus TUEBOKILLA Eisso. 

 TuEBONiLLA (Chemnitzia) coalyillensis Meek. 



Plate 9, figs. 5 a and 5. 



TurUnella (Cliemnitzia?) coalvillensis IVIeek, 1873, An. Eep. Geol. Surv. Terr. U. S. for 

 1872, p. 505. 



This species, together with some others, are included in this paper 

 mainly for the purpose of publishing the illustrations of them which were- 

 prepared by Mr. Meek a short time before his death, and which he had 

 no opportunity to pubhsh. In most cases, httle or no additional infor- 

 mation concerning these species has been obtained, and therefore his 

 descriptions and remarks alone are given as he originally wrote them. 



" Shell elongate-conical ; volutions ten or eleven, moderately convex , 

 last one not much produced below, rounded or sometimes obscurely 

 subangular around the middle ; sutiu-e well defined ; aperture rhombic- 

 suboval, being angular above and apparently a little so below ; inner 

 lip slightly thickened, rather deeply arched, a little reflected and closely 

 appressed below ; outer lip thin. Surface ornamented by rather strong^ 

 simple, regular, nearly or quite straight, vertical ridges, crossed by regu- 

 larly disposed revolving lines (about ten or eleven of the ridges and five 

 20 GS 



