PLATE V. 



Enchodus petrosiis Cope. 

 Showing fragmentary skull and complete spinal column: abv, ab- 

 dominal vertebrae; art, left articular; ang, angular; br, branchiostegals; 

 cdr, caudal rays; cdv, caudal vertebrae; den, dentary; fr, frontal; 

 hm, hyomandibular; h, hasmapophysis ; hs, haemal spines; hy, hypural; 

 iop, interopercular; ms, mesopterygoid; mt, left metapterygcid ; int', 

 right metapterygoid; mx, maxillary; tis, neural spine; n, neurapophysis; 

 op, opercular; pal, palatine; ph, a pharyngeal; ph', probably one of the 

 pharyngeals; pmx, premaxillary ; pop, preopercular; pst, post-temporal; 

 par, preorbital; r, ribs; sop, subopercular; x, undetermined bone; y, 

 probably a portion of the post-temporal; scls, supraclavicles. x Vi- 

 No. 807. 



