42 CRETACEOUS AND TERTIARY FISH. 



I have included this species entirely on the authority of Dr. 

 Eastman, 1 who says that Cope partly, at least, determined ap- 

 parently young examples of the present species as Oxyrhina 

 minutus. The former also states that Cope's determination is 

 further practically incorrect, and that some are Isurus^ desorii 

 and others Bulamia. 



Formation and locality. Cope's material was from the Mio- 

 cene of Cumberland County. 



Isurus SP. 



Oxyrhina sp. Cope, Rep. U. S. Geol. Surv. Terr. Hayden, II, 1875, p. 296. 

 (Greensand No. 4.) 



A species with flat but narrower crown than the last 

 [Oxyrhina extenta Leidy], and with perfectly smooth cementum, 

 the base of the latter being- serrulate in the convex side of the 

 crown. No denticles. Crown with a lateral curvature. (From 

 Cope. ) 



Formation and locality. Common in the "greensand, No. 4, 

 New Jersey," according to Cope, though I have no examples. 



Isurus sp. 



Oxyrhina sp. Cope, Rep. U. S. Geol. Surv. Terr. Hayden, II, 1875, p. 296. 

 (Greensand No. 4.) 



With crown flatter and broader than the last; frequently 

 oblique, but not curved, and not infrequently with lateral den- 

 ticles. Cementum smooth, except a short distance from the base 

 on the convex side striate-grooved. (From: Cope.) 



Formation and locality. Common in the "greensand, No. 4, 

 New Jersey," according to Cope. It seems possible this may be- 

 long with Lamna elegans, representing its short posterior teeth. 



Genus LAMNA Cuvier. 



Lamna Cuvier, Regne Animal, II, 1817, p. 126. Type Squalus cornubicus 

 Gmelin, restricted by Gill, Ann. Lye. N. Hist. N. Y., VIII, 1861, p. 32. 



Lamia Risso, H. N. Eur. Merid., Ill, 1826, p. 123. Type Squalus cornubicus 

 Gmelin, monotype. (Preoccupied in insects.) 



Selanonius Fleming, Brit. An., 1828, p. 169. Type Squalus selanoneus 

 Walker, monotype. 



1 Md. Geol. Sun-. Miocene, 1904, p. 81. 



