616 



HISTORICAL GEOLOGY. 



pace is nearly 10 inches square, the toothed-edge of the mandible 1^ inches 

 long, and the whole length probably over 4 feet (Hall). In addition, a 



960-962. 



960. 



960 a. 



Placoderms. — Fig'. 960, Bothriolepis Canadensis (x J), dorsal view; 960 a, id. ventral view ; from "Whiteaves - 

 m. v., middle ventral plate; a. m. v., anterior middle ventral; a. v., anterinr ventral; p. v., posterior ven- 

 ial; 961, terminal part of pectoral limb of a Bothriolepis (Cope); 962, plate of a Bothriolepis (Leidy). 



963. 



CoooosTEiD Fishes. — Figr. 963 restored ventral plates of Holonema rugosum (x J), from H. S.Williams; 

 964, restored ventral plates of Phlyctsenaspis Acadica of Whiteaves (x J), from' Traquair. 



species, related apparently to Limulus (Fig. 959), has been found in the 



