Raymond : Gastropoda of the Chazy Formation. 183 



to the band, then turn more sharply backward in crossing the angle, 

 which is a little rounded. On the under surface they turn sharply 

 forward, then back again toward the columella. 



Locality. — The best specimens have been found in the lower part 

 of the Chazy at Plattsburgh, New York, with Scalites angulatus and 

 Bucania siilcati?ia. It occurs also at Chazy, New York, and at Mon- 

 treal, Canada. 



The figured specimen is in the Yale University Museum. 



Genus Raphistomina Ulrich and Scofield. 

 Raphistomina undulata Raymond. 



(Plate XLVIII, figures 7-10.) 

 Raphistomina undulatum Raymond, 1906, Annals Carnegie Museum, 



Vol. Ill, p. 576. 



In the locality at Sloop Bay there occurs a Raphisloma-like shell which 

 cannot be referred to any of the preceding species. It differs from 

 them, not only in surface markings but also in its much more lenticu- 

 lar form. It belongs, strictly speaking, with the group of shells for 

 which Ulrich erected the genus Raphistomina. The corrugated sur- 

 face of the body whorl serves to identify this species very readily. 



Description. 



Shell small, four or five whorls, lenticular, the spire rather high, the 

 under portion rounded, depressed, not subconical as in Raphistoma 

 stamineum. The first three or four volutions of the cast are smooth, but 

 the surface of the body whorl is marked by numerous small folds which 

 run from the suture diagonally across the volution. The margin is 

 acute, rounded and just beneath it is a narrow concave space. Below 

 this the shell is gently convex for a short distance, then flat to the 

 umbilicus, which, in the cast, is open. 



Locality. — This shell has so far been found only in the Middle 

 Chazy at Sloop Bay, Valcour Island, New York. The type is in the 

 Yale University Museum. 



Genus Scalites Emmons. 



Scalites angulatus Emmons. 



(Plate XLVIII, figures 13-16.) 



Scalites angulatus Emmons, 1842, Geological Survey of New York, p. 



312, fig. 1. 



