40 



CRETACEOUS AND TERTIARY FISH. 



Fig. io. — Isnrus acuminatus (Morton), i, Burlington Co. (Conrad) ; 2, 

 Monmouth Co. (Knieskern) ; 3, Bridgeton (H. B. Abbott) ; 4, Burlington 

 Co. (Conrad) ; *5-6, Vincentown (Dick). 



Shark River (T. A. Conrad), 1 from Deal [Manasquan or Shark 

 River formations, probably the former, K.] and 3 from Eong 

 Branch [Hornerstown ? K.], all without donor, 2 from Burling- 

 ton County (T. A. Conrad), 2 from Vincentown [Manasquan 

 formation, K.] (T. A. Bryan), 2 from Mullica Hill [Navesink 

 marl ? K.] in Gloucester County (C. C. Abbott), 2 from Allo- 

 waystown in Salem County (H. C. Yarrow), and 1 from the 

 Miocene of Cumberland County along the "Bridgeton Pike" (C. 

 C. Abbott). 



Isurus siLUMANii (Gibbes). 



Oxyrhina minntus (nee Agassiz) Cope, Proc. Amer. Philos. Soc. Phila., 

 XIV, 1875, p. 362. (Cumberland Co. Miocene.) 



Teeth moderately compressed, rather thin, and formed as a 

 moderate isoceles triangle. Crown variably curved slightly out- 

 ward, or inwards toward apex. Outer coronal surface flattened 

 or slightly convex, inner surface flattened or slightly convex, and 

 latter without basal vertical folds. Apex deflected, sometimes 

 strongly so, to one side. Cutting-edges entire. Usually at base 

 on either or each side one or two obsolete broad cusps, low, and 

 their edges also entire. Roots short or moderate, outer surface 

 flattened or slightly concave, inner surface bulging in prominent 

 convexity, and lower profile forming a moderate emarginate 

 blunt angle. Ends of roots deep, though not produced. Reaches 

 a length of 34 mm. This description from 24 examples from the 

 Calvert formation of Charles County, Md., in the Miocene. 



