DEVONIAN FISHES OF IOWA 



263 



the other, which Dawson figures, displaying the entire outline. 

 This latter exhibits no trace of dorsal ridge scales ; impressions 

 of five or six such, however, occur in advance of the dorsal fin in 

 the more poorly preserved specimen. Examination shows that 

 these ridge-scales are distinctly not truncated behind, as Daw- 

 son supposed, but on the contrary are obtusely pointed. Con- 

 sequently the outline sketch given in Fig. 18 d of his Notes and 

 Addenda to the "Geology of Canada" (3d edition, 1878, p. 100) 

 requires to be emended in this particular. 



Fig. 39. 



Fig. 39. Rkadinichthys modulus Dawson, 

 county, New Brunswick. Cotypes, x 1-1. 



Lower Carboniferous; Beliveau, Albert 



The ornamentation of the flank scales as represented in Fig. 

 18b of the same work is also imperfectly shown. The posterior 

 margin of the scales is indeed strongly serrate, and the exposed 

 surface is covered by from five to six relatively coarse plica- 



