CATALOG OF THE FOSSIL FISHES IN THE CARNEGIE MUSEUM. 



417 



similar to that already observed in Hypsocormus, and the convoluted appearance of 

 which is due to the presence of numerous transverse fibrous bands and ridges. From 

 analogy with recent forms in which similar bands occur, it may be presumed that 

 the interior was partitioned off by transverse septa extending between the ridges. 



40. Asthenocormus retrodorsalis, sp. nov. 

 T^/pe.— Imperfect fish; Carnegie Museum (Cat. Nos. 4863, 4863a, 48636). 



A species nearly equalling the type of the genus in size, and resembling it in 

 general form and proportions, but distinguished from it chiefly by characters of 

 the median fins and the dentition. Pelvic fins present, and the low triangular 

 dorsal fin arising behind the anal. 



This species is established upon the evidence of a single nearly complete indi- 

 vidual, preserved in counterpart, from the Lithographic Stone of Kelheim, Bavaria, 

 and contained in the Bayet Collection of the Carnegie Museum. The head and 

 anterior portion of the trunk have been considerably crushed and deformed, but 

 the remainder of the body is preserved without distortion and shows the lateral 

 aspect, the position of all the fins being clearly indicated. 



Fig. 6. Asthenocormus retrodorsalis, sp. nov. C. M. Cat. Foss. Fishes,"lNos. 4863 "and 4863a.^X i- 



As denoted by the specific title, the dorsal fin is remote, arising behind the 

 origin of the anal, and is much shorter than the latter. The dorsal fin consists of 

 comparatively few rays, which posteriorly rapidly decrease in size. The anal fin 

 has become detached, but its internal supports are preserved intact ; these depend 

 almost vertically from the haemal spines, and are seen to be about thirty in number. 

 The small pelvic pair is situated midway between the pectorals and anal fin. The 

 proximal portions of both pectorals are preserved, but the distal two thirds have 

 been broken away. The caudal fin is complete, exhibiting the very fine sub- 

 division of the rays at its hinder border, but no fulcra along the anterior margin. 



New and interesting features are presented by the dentition of this species. 



