BUFFALO SOCIETY OF NATURAL SCIENCES 149 



Dittodus sp. 



E 2028 One tooth, 6 mm. in height, on a piece of black shale. It 

 consists of two cones without a median denticle (perhaps 

 broken away?). The surface of the cones bears a few 

 faint vertical striations, and the tooth may possibly 

 belong in D. priscus. The root is injured. 



Rhinestreet shale; shore of Lake Erie, near Sturgeon 

 Point, New York. 



E 2559 One tooth with fragments of others, somewhat weathered. 

 The ornamentation, if any there was, has entirely dis- 

 appeared, but in size these teeth are comparable with 

 D. priscus. 



Pyrite layer of the Tully horizon, Cazenovia Creek, 

 near Springbrook, N. Y. Collected by W. L. Bryant. 



IV. Euselachii 

 Family PETALODONTID^ 



Petalodus ohioensis Safford^^ 



E 2087 One tooth. Bituminous coal series; Northwestern Penn- 

 sylvania. Carll collection. 



Family PSAMMODONTID^ 



Psammodus angularis Newberry & Worthen 

 E 2492 One tooth. Chester limestone? Illinois. 



Helodus rugosus Newberry and Worthen 



E 2080 One tooth. Carbonic; Crawford County, Pennsylvania. 

 Carll collection 



E 2081 One tooth. Carbonic; Franklin, Venango County, Penn- 

 sylvania. Carll collection. 



'*For synon3rmy of this and the following species, see Hay, O. P.: Bibl, attd Catal. Fos. Vert. 

 N. A., igo2, p. 278, el passim. 



