BUFFALO SOCIETY OF NATURAL SCIENCES 



141 



Acanthodjes concinnus Whiteaves 



(PI. 51, figs. 2, 4; text-fig. 50) 



Among the specimens collected by Mr. Bryant in the Upper De- 

 vonic at Scamnenac Bay, Quebec, in 191 5, is a large example of 

 Acanthodes concinnus, 29 cm. in length. This is about twice the size 

 of the largest specimen figured by Whiteaves,^^ and thus proves that 

 the species attained much larger proportions than was hitherto 

 supposed. The species is readily distinguished by the scale ornamen- 

 tation (PI. 51, fig. 2), and by the relatively weak spines. 



Fig. 50. Acanthodes concinnus Whiteaves. Outluste of a Nearly Complete 



Shark. X \ 



All the fin-spines are present (although incompletely preserved,), and apparently 

 in their proper positions. 



a, anal fin-spine; d, dorsal; p, pectoral; v, ventral. The two fragments of spine 

 seen in front of the pectorial spine are apparently parts of the fin-spine of the 

 opposite side. Note the ray-like structure in the lower lobe of the caudal. 

 E 2485 



E 2485 A shark, 29 cm. in length (fig. 50), in side view, on shale. 

 The ventral margin of the trunk was lost through the 

 flaking out of a thin superficial layer of the rock; and the 

 tip of the caudal for about i cm. is also missing. The 

 mouth is widely opened. One pectoral fin-spine is the 

 only spine completely preserved (PI. 51, fig. 4). It is 

 somewhat shifted from its natural position, and measures 

 19 mm. in length (incomplete at proximal end?). Of the 

 other fiji-spines only the proximal ends are preserved. 

 The dorsal spine is inserted a Httle back of the middle of 



s« Whiteaves, J. F.: Illustrations of the fossil fishes of the Devonian rocks of Canada. Part J. 

 Trans. Roy. Soc. Canada, iv, 107, pi. x, figs, i, la, 1886; Part II, in vol. vl, pi. v, fig. 2, iSSq. 



