﻿4;U ACTIXOPIKRYGIl. 



Genus GONATODUS, Traquair. 



[Quart. Journ. Geol. Soc. vol. xxxiii. 1877, p. 555. ] 



Syu. Microconodus, R. H. Traquair, Ganoid Fishes Brit. Carb. Form. 

 (Pal. Soc. 1877), p. 12 (name only). 



Trunk fusiform. Mandibular suspensorium slightly oblique ; 

 teeth robust, styliform, more or less bent, forming a single, regular, 

 close series on the margin of each jaw. Fins well developed, 

 consisting of numerous robust, closely-jointed rays, distally branch- 

 ing: fulcra small. Base of pelvic fins short; dorsal and anal fins 

 triangular, the former arising somewhat in advance of the latter ; 

 caudal fin forked. Scales large, smooth or feebly ornamented. 



Gonatodus pun c tat us ( Agassi z). 



1835. Amblypterus punctatus, L. Agassiz, Poiss, Foss. vol. ii. pt. i. 



p. 109, pi. iv. c. fig. 4 (non figs. 3 ; 5-8). 

 (?) 1872. Amblypterus anconocechmodus, R. Walker, Trans. Edinb. 



Geol. Soc. vol. ii. pt. i. p. 119, with plate. 

 1877. Gonatodus punctatus, R. H. Traquair, Quart. Journ. Geol. Soc. 



vol. xxxiii. p. 555, and Proc. Roy. Soc. Edinb. vol. ix. p. 265, 



and Ganoid Fishes Brit. Carb. Form. (Pal. Soc), pi. ii. figs. 4, 5. 

 1890. Gonatodus punctatus, R. H. Traquair, Proc. Roy. Soc. Edinb. 



vol. xvii. p. 391. 



Type, Imperfect fish : Edinburgh Museum. 



The t3 T pe species, attaining a length of about 0-16. Maximum 

 depth of trunk contained about three and a half times in the 

 total length. Head and opercular apparatus small, triangular, 

 occupying about one-fifth, of the total length ; external bones with 

 sparse stria tions, often interrupted, those of the operculum and 

 suboperculum transverse or obliquely directed downwards ; dentition 

 consisting of acutely pointed teeth, each inclined first a little 

 inwards, then bent outwards at an obtuse angle, with the apex 

 finally erect. Pelvic fins arising nearer to the anal than to the 

 pectorals. Scales very large, ornamented with close, transverse, 

 and partly concentric, striations, becoming feeble or absent in the 

 caudal region : hinder border delicately serrated. 



Form. 6f Log. Calciferous Sandstone Series : Midlothian and 

 Fifeshire. 



P. 842 Well-preserved specimen, in counterpart, wanting the 

 pectoral fins and part of the caudal ; Wardie. near Edin- 

 burgh. Egerton Coll. 



