138 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 

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TUB[TLOSTIUM DICKHAUTl White. 



(Plate I, Figs. T2aiull3.) 



Spirorhls? dickliaitti AVhite, 1880, Proc. U. S. National Museum, vol. iii, p. 161. 



Since the description of this species was published (loc. cit,), certain 

 fragments have been brought to light which indicate th?,t this shell 

 really belongs to a group for which Dr. Stoliczka in Pal. Indica, vol. \h 

 p. 237, proposed the generic name Tithidosihim. Our species is indeed 

 very closely related to his T. dlscoideum (op. cit., pi. xviii, ligs. i'0-25;. 

 Che tubular prolongation of the mouth is one of the distinguishing 

 features of this groux) of shells. Our specimens do not show this' fea- 

 ture clearly, but it is probable that that portion of the shell has been 

 broken off, as is suggested by the added outline in figure 12. 



CANTHAKUS ? JULESBUKGENSIS (sp. UOV.). 

 (Plate I, Figs. 1 and 'J.) 



Shell short fusiform ; spire moderately elevated ; volutions convex, 

 apparently five or six in number, obscurely flattened upon the outer 

 side and obliquely llattened or slightly concave upon the distal side; 

 the outer side of the volutions marked by four strongly-raised revolving 

 ribs (including the two prominent ones which border the flattened por- 

 tion of the outer side) which are narrower than the si)aces between them; 

 the distal side marked by two or three similar, but less distinct revolving 

 ribs, the convex proximal side of the last volution marked by numerous 

 ribs similar to those of the outer side, but which decrease in prominence 

 anteriorly after the flrst two; longitudinal varices irregular, somewhat 

 numerous, giving the shell, in connection with the revolving ribs, a 

 rugose aspect. 



Length about oO millimeters; diameter of the last volution 22 milli- 

 meters. (Museum Xo. 114G8.) 



Only a single example of this species has been discovered, and that 

 is imperfect, as shown in the ligure. Its characteristics are, however, 

 so well marked that it may be readily recognized as distinct from any 

 hitherto-described form. 



Position and locality. — Later Cretaceous stra.ta (equivalent with the 

 Fox Hills and Fort Pierre Groups of the Upper Missouri Eiver region) 

 in the vicinity of Julesburg, Colo., where it was obtained by Mr. W. 

 Cleburn. 



LUCINA PROFUNDA White. 



(Plato I, Figs. 5au(l(>.) 

 Ludni', profunda Wliite, 1880, Proc. U. S. National Museum, vol. iii, p. 158. 



