358 UNITED STATES GEOLOGICAL SURVEY OF THE TERRITORIES. 



probably include other Tertiary (onus ; but I am not aware of its existence 

 in the Cretaceous rocks, or among living species. 



The section Mesorhytis occurs in the Cretaceous, and, apparently, also 

 in the Tertiary. I am not sure that it ought to be included, even as a distinct 

 subgenus, under Fasciolaria. 



Fasciolaria bii <• c i 11 o i «l c s , M & H. 



Plate 31, figs. 8, a, b, c, d. 



Fasciolaria buceinoides, Meek and Hayden (1956), Proceed. Acad. Nat. Sci. Philad., VIII, 67. — Meek (1864), 

 Smithsonian Check-List N. Am. Cret. Fossils, 21. 



Shell small, rather short-fusiform; spire moderately elevated, composed 

 of five to five and a half convex volutions: last turn somewhat gibbous, forming 

 more than half the entire length, and contracting rather abruptly below into 

 the rather short canal: suture distinct or slightly channeled; surface orna- 

 mented by fine, regular lines of growth, with sometimes small, obscure, 

 vertical folds, which are crossed by rounded, little revolving bands or raised 

 lines, equal to, or slightly broader than, the depressions between ; on these 

 bands, as well as in the intervening depressions, faint traces of very fine 

 revolving strise may sometimes be seen by the aid of a lens; aperture narrow- 

 oval, angular above, and tapering below; outer lip thin, but apparently thick- 

 ened and crenulate within, at intervals of about three or four times to each turn 

 of the spire; columella a little twisted, and provided with two well-defined, 

 oblique plaits, that are so tar around as not to be clearly seen when' the aper- 

 ture is filled with rocky material that cannot be removed. 



Length, 118 inches; breadth, 0.58 inch. Apical angle convex; diver- 

 gence, 54° to 57°. 



The vertical folds are never very distinct, and in many cases they are 

 almost entirely obsolete. Sometimes they exist on the spire, but generally 

 they are only developed on the upper part of the last turn, where they occa- 

 sionally present the appearance of being slightly nodose, in consequence of 

 the prominence of the revolving bands. These bands, of which about seven 

 or eight may be counted on the first turn above the body-whorl, are usually 

 very distinct and regular on all parts of the shell; in a few instances, how- 

 ever, they are rendered irregular, or alternately larger and smaller, especially 

 on the lower part of the body-volution, by the development of a smaller one 

 in each of the grooves between. Although the plaits on the columella are 



