﻿pal^oniscid^:. 501 



Elonichihys browni, R. H. Traquair, Quart. Joum. Geol. Soc. 

 vol. xxxiii. (1877), p. 553: Palcuoniscus (Elonichthys) 

 brownii, J.W. Dawson, Canadian Nat. n. s. vol. viii. (1877), 

 p. 339, and Acadian Geology, Suppl. (1878), p. 101 : 

 Palceoniscus brownii, C. T. Jackson, Rep. Albert Coal 

 Mine (1851), p. 22, pi. i. fig. 2, and Proc. Boston Soc. 

 Nat. Hist. vol. iv. (1852), p. 139.— Lower Carboniferous ; 

 Hillsborough, Albert Co., New Brunswick. 



Elonichthys speciosus : Oyrolepis speciosus, A. Fritsch, Sitzungsb. 

 k. bohm. Gesell. Wiss. 1877, p. 46. — Lower Permian 

 (Gas- coal); Bohemia. [Jaws and scales ; Royal Bohemian 

 Museum, Prague.] 



Here possibly may also be placed the undescribed species, Pro- 

 palceoniscus agassizi, A. Pomel (Catal. Method. Vert. Foss. 1853, 

 p. 133), from the Coal-Measures of Bert-Montcombroux, Allier. 



Genus ACROLEPIS, Agassiz. 

 [Poiss. Foss. vol. ii. pt. i. 1833, p. 11, and ibid. pt. ii. 1844, p. 79.] 



Trunk elongated, gradually tapering from the occiput. Mandi- 

 bular suspensorium oblique ; dentition consisting of a series of 

 large, well-spaced conical teeth, and more numerous small teeth 

 irregularly arranged and somewhat clustered ; head and opercular 

 bones strongly ornamented with tuberculations, often fused into 

 short vermiculating rugae and striae. Fins well developed, with 

 fulcra, the rays branching distally, covered with dense ganoine, and 

 the more robust sculptured. Pelvic fins with comparatively short 

 base-line, dorsal and anal fins triangular, at least as high as long, 

 the dorsal opposed to the space between the pelvic and anal fins ; 

 upper caudal lobe robust, the fin deeply forked and equilobate. 

 Scales thick, large, or of moderate size, deeply imbricating, exter- 

 nally enveloped in dense ganoine, sculptured with coarse oblique 

 grooves and ridges, sometimes bifurcating ; flank-scales rarely 

 deeper than broad, ventral scales narrow ; the large scales of the 

 caudal pedicle extending well up the base of the superior caudal 

 lobe. 



The known species of this genus are all of large size. 



Acrolepis sedgwicki, Agassiz. 



1829. "Fossil Fish," A. Sedgwick, Trans. Geol. Soc. [2] vol. Hi. 

 p. 117, pi. viii. figs. 3, 4. 



