PLATE XXVIII. 
PAGE 
Figs, la, lb. Squatina occidentalis n. sp 71 
la. Outer face of tooth (type specimen) showing downward prolonga- 
tion of the enamel below the base of crown. Plum Point. 
X 4/3 
lb. Inner face of the same specimen. 
Fig. 2. Raja { ?) dux Cope 72 
2. Superior aspect of a detached and considerably abraded dermal 
tubercle. (Type specimen.) Charles County near the Patuxent 
River. Acad. Nat. Sci.. Phila. 
Figs. 3a, 3b. Myliobatis gigas Cope 73 
3a. Oral surface of the upper dental pavement of an adult individual, 
the anterior end (shown uppermost in the figure) fractured 
and imperfect. (Type specimen.) Charles County near the 
Patuxent River. Acad. Nat. Sci., Phila. 
3b. Transverse view of the same specimen, taken across its posterior 
end (at bottom of Fig. 3a). 
20 
