P. E. Raymond — Fauna of the Chazy Limestone. 375 



which on the internal cast is represented by a rounded conical 

 elevation. The posterior scar is large and close to the hinge 

 line. 



Length 51 mm , height 28 mm . 



Length 37 mm , height 20 mm . 



Locality. — From the Ay lmer sandstone, about 60 feet above 

 the high-water mark of Lake Deschenes, at Ay lmer, Quebec. 

 Collected by T. W. E. Sowter, for whom it is named. The 

 type is in the Yale University Museum. 



GASTROPODA. 



Archinacella f deformata (Hall). 



Orbicula ? deformata Hall, 1847, Pal. N. Y., vol. i, p. 23, pi. iv bis, figs. 

 10a, 10b. 



Metoptoma f dubia Hall, ibid., figs. 11a, lib. 



Stenotheca dubia Whitfield and Hovey, 1898, Catalogue of Type and Fig- 

 ured Specimens in the American Museum of Natural History, Bull. 

 Amer. Mus. Nat. Hist., vol. «xi, p. 58. 



An examination of the types shows that Whitfield was right 

 in regarding the specimen named Orbicula? deformata by 

 Hall as identical with Metoptoma f dubia, which Hall described 

 on the same page. His species, however, must take the first 

 specific name applied to it, even though given under the mis- 

 apprehension that it was a brachiopod instead of a gastropod. 



The generic reference is uncertain as no specimens have 

 been found which show either muscle scars or pronounced 

 surface markings. It does not seem possible to leave it either 

 in the genus Metoptoma, where Hall doubtfully put it, or in 

 Stenotheca, where it was placed by Whitfield. In general 

 form it most resembles the numerous species of Archinacella 

 described by Ulrich and Scofield, to which it may be referred 

 until better examples are obtained. The individual specimens 

 of this shell are abundant and the characters are quite con- 

 stant. It is easily recognized by the low form and almost 

 marginal position of the beak. 



Scenella pretensa sp. nov. 



Shell small, aperture narrowly elliptical in outline. Height 

 about equal to the greatest diameter of the aperture. Beak 

 small, pointed backward, but not incurved. Posterior slope 

 nearly straight. Anterior slope convex above, becoming 

 straight below. Surface smooth, except for a few low concen- 

 tric undulations near the base. Beak a little behind the 

 middle. 



The greatest diameter is ll mm ; the shortest is 6*5 mm . Height 

 ll-5 mm . 



