408 C. K. EASTMAN — JURASSIC FISHES FROM BLACK HILLS 



Explanation of Plates 



Plate 45. — Pliolidophorus americanus E. 



Figures 1, 2. — Full grown individuals seen from the right side, reproduced from 

 photographic negatives without retouching. Both figures very 

 nearly of the natural size. 



Figure 3. — Photograph of caudal portion of another adult individual. 



Plate 46. — Pliolidophorus americanus E. 



Figures 1, 2. — Enlarged photo-drawings of adult individuals; the details of figure 

 , 2 taken in part from opposite half of counterpart. Both figures 



enlarged about f natural size. 



Platk 47. — Pliolidophorus americanus E. (pars?) 



Figure 1. — Photogi'aph of large, fragmentary specimen with roughened scales, 

 possibly belonging to a distinct species. Natural size. 



Figure 2. — Photo drawing of small individual seen from ventral aspect, showing 

 mandibles, premaxillae, branchiostegal rays, details of fin struct- 

 ure, etcetera. One-fifth larger than natural size. 



FiQUKK 3. — Photo-drawing of small individual with numerous scale-series, convex 

 operculum and strong maxilla, possibly belonging to a distinct 

 species. Natural size. 



Figures 4, 5. — Posterior half of young individual preserved in counterpart, show- 

 ing delicate squamation and conspicuous lateral line. 



Plate 48. — Amiopsis {f) dartoni sp. nov. and an undetermined ganoid. 



Figure 1. — Photograph of naturally associated fragments of large fish with thin 

 cycloidal scales. Clavicles and operculum shown near the top, 

 fin rays (both pectorals, pelvic and anal), ribs, and scales toward 

 the bottom of figure. Five-sixths natural size. 



Figure 2. — Detached scale, two-thirds larger than natural size. 



Figure 3. — Pectoral fin of undetermined ganoid, proximal end at left-hand side 

 of figure, distal below and to the right. One-third larger than 

 natural size. From photo-drawing by Mr J. H. Blake. 



