PLATE XXIX.. 
PAGE 
Figs, la, lb. Myliobatis gigas Cope 73 
la. Oral surface of lower dental pavement, somewhat worn, and 
showing line of longitudinal striae or fissures of the gano- 
dentine radiating backwards and outwards. Charles County- 
near the Patuxent River. Type of the so-called " M. vicomi- 
canus." Acad. Nat. Sci., Phila. 
lb. Transverse view of the same specimen at its posterior end 
(across the bottom of Fig. la). 
Figs. 2a, 2b. Myliobatis paciiyodon Cope 75 
2a. Oral surface of imperfect lower dental pavement, the anterior 
end shown uppermost. (Type specimen.) Charles County 
near the Patuxent River. Acad. Nat. Sci., Phila. 
2b. Transverse view of the same specimen. 
Fig. 3. Myliobatis fkangens n. sp 75 
3. Oral surface of imperfect lower dental pavement, somewhat worn, 
and showing curved outline of the anterior depression due to 
wear. (Type specimen.) Charles County near the Patuxent 
River. Acad. Nat. Sci., Phila. 
Fig. 4. Myliobatis or Trygon (?) sp 92 
4. Portion of large caudal spine of an eagle or sting-ray. Charles 
County near the Patuxent River. Acad. Nat. Sci., Phila. 
Fig. 5. AicTOBATis arcuatus Agassiz 76 
- 5. Inferior aspect of fragmentary tooth. St. Mary's River. 
Figs. 6a, 6b. Notidanus rRi.MioENius Agassiz 77 
6a. Inner aspect of tooth, the root much worn away. Plum Point. 
6b. Outer aspect of the same specimen. 
