MARYLAND GEOLOGICAL SURVEY 71 



Class I ISCcS. 



Subclass ELASMOBRANCHII. 



Order SELACHII. 



Suborder TECTOSPONDYLI. 

 Family SQUATINIDAE. 



Genus SQUATINA Dumeril. 

 A single characteristic toc-th of the " Angel-fish/' Squatina, without 

 lateral denticles and having a small median downward prolongation of 

 the crown upon the front of the root below the large cone, was obtained 

 by the Survey from the Calvert formation at Plum Point. The species 

 appears to be distinct, and is interesting as being the first to be defi- 

 nitely recognized from this continent. It is probable, however, that 

 the small undetermined teeth figured by Leidy in the Post-Pleiocene 

 Fossils of South Carolina (Plate XXV, Figs. 9-13), also belong to 

 Squatina. 



Squatina occidentalis n. sp. 

 Plate XXVIII, Figs, la, lb. 



Description. — Crown erect and comparatively stout, convex on both 

 faces, and with sharp cutting edges. Enamel forming a blunt projec- 

 tion in front below the base of the crown, and extending as far as the 

 lateral extremities of the root on the outer face. Eoot with a flat 

 triangular inferior surface, and nutrient foramen situated in a slight 

 median depression; upper surface of root elevated into a prominent 

 transverse fold extending from the base of the crown to the innermost 

 angle of the root. Total height of tooth in the type-specimen 6 mm.; 

 length of base 9 mm. 



Occurrence. — Calvert Formation. Plum Point. 



Collection. — Maryland Geological Survey. 



Family RAJIDAE MUller and Henle. 



Genus RAJA Cuvier. 

 It is customary to assign either to this genus or to Trijgon the majority 

 of detached dermal tubercles found in the Tertiary of various European 



