268 G. F. Eaton — Collection of Triassic Fishes at Yale. 



EXPLANATION OF PLATES. 



Plate V. 



Figure 1. — Semionotus fultus ; dorsal fin. 



Figure 2. — S. fultus ; pectoral fin. 



Figure 3. — S. fultus ; anterior flank scales. 



Figure 4. — S. fultus ; posterior flank scales. 



Figure 5. — S. Marshi; scales from 12th obliqne row, a little below lateral 



line. 

 Figure 6. — S. micropterus ; pectoral fin. 

 Figure 7. — S. micropterus; anterior flank scales. 

 Figure 8. — S. micropterus; posterior flank scales. 

 Figure 9. — S. Marshi; posterior flank scales. 

 Figure 10. — S. Marshi ; last scale of anterior dorsal ridge. 

 Figure 11. — S. micropterus ; last scale of anterior dorsal ridge. 

 Figure 12. — S. Marshi ; scales of 7th and 8th oblique rows, immediately 



below lateral line. 

 Figure 13. — S. micropterus ; dorsal fin. 



All the figures are twice natural size. 



# Plate VI. 



Figure 1. — S. Marshi; head ; natural size. 



Fr. , frontal ; Pa. , parietal ; S. t . , supratemporal ; Sq. , squa- 

 mosal ; P.or., postorbital ; Op., operculum; P. op., preoper- 

 culum ; I. op., interoperculum ; S.op., suboperculum . 

 Figure 2. — S. Marshi ; lower flank scale, showing articular process ; natural 



size. 

 Figure 3. — Semionotus, sp.; lower flank scales, showing double articulation :; 



four times natural size. 

 Figure 4. — Semionotus, sp.; premaxillge ; natural size. 

 Figure 5. — S. ovatus : dorsal fin ; twice natural size. 



