﻿35S 



CROSSOPTERYGII. 



P. 4587. Type scale, well preserved, much resembling the original 

 of Roemers fig. 2, but less symmetrical ; shown, of three- 

 halves the natural size, in PI. XVI. fig. 3 ; Volpersdorf, 

 Glatz. Ennislcillen Coll. 



P. 4586. Right operculum, 0*019 in depth, and equally broad, the 

 hinder border sharply angulated about its middle point, 

 and the lower border twice as long as the upper : Yolpers- 

 dorf. Ennislcillen Coll. 



The following specimens also pertain to this genus : — 



P. 789. Two small scales, inner aspect; Coal-Measures, Pictou, 

 Nova Scotia. Egerton Coll. 



Genus GYROPTYCHIUS, M'Coy. 

 [Ann. Mag. Nat. Hist. [2] vol. ii. 1848, p. 307.] 

 Syn. Glyptolepis, L. Agassiz, Poiss. Fos3. V. G. R. 1844, p. 62 (in part). 



Body much depressed anteriorly, with ovoid scales, of which the 

 exposed portion is probably covered with a thin film of ganoine, 

 while the inner face is marked by a prominent median ridge and 

 punctations posteriorly. Head-bones tuberculated. No ossified 

 vertebrae. First dorsal fin opposed to the pelvic pair, and the second 

 dorsal to the anal ; tail almost diphycercal, the upper lobe of the 

 rhomboidal caudal fin being relatively large. 



This genus comprises fishes of small size, and is very closely related 

 to RMzodopsis : the scales appear to differ from those of the latter 

 merely in the substitution of a prominent long ridge for the median 

 inner boss. 



Gyroptychius microlepidotus (Agassiz). 



1844. Glyptolepis microlepidotus, L. Agassiz, Poiss. Foss. V. G. R. p. 65, 



pi. xxi. a. figs. 3-7. 

 1848. Gyroptychius anyustus, F. M'Coy, Ann. Mag. Nat. Hist. [2] vol. ii. 



p. 308, woodc. figs. a-c. [Woodwardian Museum, Cambridge.] 

 1855. Gyroptychius anyustus, F. M'Coy, Brit. Palaeoz. Foss. p. 596, 



pi. ii. c. fig. 2. 

 1860. Gyroptychius anyustus ?, C. H. Pander, Saurodipt., Dendrodont. 



&c. devon. Syst. p. 79, pi. vi. figs. 1-7, pi. vii. figs. 1-3. 

 1861.- Gyroptychius, T. H. Huxley, Figs, and Descrips. Brit. Organic 



Remains (Mem. Geol. Surv.), dec. x. p. 3, woodc. fig. 3. 

 1875. Gyroptychius anyustus, R. H. Traquair, Trans. Roy. Soc. Edinb. 



vol. xxvii. p. 395. 

 1888. Gyroptychius microlepidotus, R. H. Traquair, Geol. Mag. [3] 



vol. v. p. 514. 



