INYKKTIXKATK PALEONTOLOGY 



367 



Fast tularin ' i Crypto- 

 rhytw) flexicostata. 



A cut to slum 



Fasciolarial (Cr yptorliy tis) flcxicostatn M. & H. (sp.). 



Plate 19, fig. 2. 



I'nsiis ficxicostatus, Meek and Hayden il^'ili), Proceed. Acad. Nat. Sci. Pbilad., VIII, (Hi. 

 1'i.ri/nMis ! ffexicostatus, Meek (1864), Smithsonian Check-List X. Am. Cret. Fossils, 22. 



Shell thin, rather short-fusiform; spire moderate, slender Fl &- 4(i - 



above, and acute al the apex, consisting of six and a half to 



seven convex volutions: last or body volution somewhat 

 ventricose, slightly shouldered above, and abruptly contract- 

 ing to the canal below; suture distinct: flexuous vertical 

 costae well defined on all the volutions, excepting perhaps 

 some of those near the apex of the spire, and near the aper- 

 ture on the last one, each terminating at the slightly-defined the » ta «! P roml " 



J nent phut at the 



shoulder above, in a small node; space between these nodes ba.se of the eolu- 



i i • p r l mella.* 



and the suture narrow and concave; entire surface finely 

 cancellated by small vertical and revolving stria?, the latter of which become 

 somewhat stronger, more irregular, and more oblique on the lower part of the 

 body-volution; aperture obovate ; outer lip broadly and rather deeply sinuous 

 above the middle, and prominent below. 



Length, exclusive of the canal, 1.13 inches; breadth of body-volution 

 with lip broken), 64 inch ; length of aperture exclusive of the canal, 0.50 

 inch; breadth of same, 0.2') inch. Angle of spire with slightly concave, or 

 nearly straight slopes, and a divergence of 46°. 



Like the last, this has long been viewed as a shell of doubtful relations. 

 ( m recently breaking one of the specimens, however, I made the interesting 

 discovery that it has one very prominent, oblique, sharply-elevated plait on 

 the columella, a little above the position of those of the typical forms of 

 Fasciolaria; though it is not, as in the latter, continued around far enough to 

 lie seen in unbroken specimens. As it agrees exactly with the last in surface- 

 markings, and the smoothness of its outer lip within, it evidently fells into 

 the same section, and, indeed, is even closely allied specifically. It differs, 

 however, in having a less elevated and more slender spire, a more ventricose 

 body-volution, and particularly in having the plait of its columella lower on 

 the columella, as well as more prominent and less oblique. 



Among foreign Cretaceous species, it may be compared with Valuta 

 monodonta, Binkhorst, from Limbourg, and an East Indian species identified 

 by Stoliczka with Voluta rigida, Baily, under the name Fasciolaria rigida. 



* Tli>' cut makes the plait continue down tin- margin of the. canal too far. 



