[NVEETEBEATE PALEONTOLOGY. 359 



small, and not always readily seen, as specimens arc usually round with the 

 aperture tilled with rock, il seems to l>e a true Fasciolaria. 



This species resembles in its external characters Bvccinuml vinculum, 

 Hall and Meek (Mem. Am. Acad. Arts and Sci. Boston, Vlll (n.s ), pi. 3, fig. 3), 

 which we now know 1o he even generically distinct. It may always he dis- 

 tinguished from that shell, even where the columella cannot he seen, by its 

 less elongate Form, shorter spire, and comparatively broader, as well as more 

 closely-arranged, revolving lines or bands. Its vertical folds are also much 

 less distincl on the upper whorls than on those of B.l vinculum. 



Locality and position. — Moreau River and Long Lake: from the Fox 

 Hills group, or formation No. 5 of the Upper Missouri Cretaceous series. 



Subgenus PIESTOCHILUS, Meek. 



Fasciolaria (Piestochilus) Scarboronglii, M. & H. 



Plate ::■-'. figs. 1. a. h. c, ./. 



Fusus Scarborough!, Meek and Hayden (1857), Proceed. Acad. Nat. Sci. Pliilad., IX, 139. 



( lavellilhes i Piestoekilus) Scarboroughi, Meek (lS(i4). Smithsonian Check-List N. Am. Cret. Fossils, 22. 



Shell rather elongate-fusiform ; spire moderately prominent, pointed at 

 the apex, with lateral slopes convex in outline; volutions about six and a 

 half, flattened to the line of the lateral slopes of the spire: last one com- 

 posing, with the canal, a little more than half the entire length of the shell, 

 sometimes slightly concave above, moderately convex around the middle, 

 and tapering rather gradually into the canal below, which is narrow, nearly 

 straight, and of moderate length: suture linear; aperture rhombic-obovate, 

 being angular above, and tapering gradually below; columella but slightly 

 arched along the middle of the aperture ; most prominent part of the thin 

 outer lip below the middle; surface marked by tine, regular lines of growth, 

 which are crossed by numerous, rather distinct, revolving lines, more or less 

 flattened on their tops, and about equaling the breadth of the grooves 

 between. 



Length, 1.42 inches; breadth, 0.67 inch; divergence of slopes of the 

 spire, 40°. 



The revolving lines of this shell are but slightly elevated, and when a 

 little worn, especially on the body-volution, seem to be somewhat rounded ; 

 but those on the spire have generally a more flattened appearance. About 

 fourteen of them may usually be counted on each turn of the spire. 



