﻿50 GANOID FISHES OF THE CARBONIFEROUS FORMATION. 



displayed ; it is pointed in shape, but not acutely so ; and its length along its anterior 

 margin is not less than 3^ inches. Thus it extends beyond the origin of the ventral, 

 which arises only 2^ inches behind the origin of the pectoral. In shape the ventral is 

 more acuminate than the pectoral, its hinder margin being more cut out ; its base of 

 attachment is If inch broad ; the length of its anterior rays nearly 3 inches; and, as the 

 extreme point of the fin is lost, it must certainly have been a little longer. The interval 

 between the ventral and the anal is rather greater than that between the former and the 

 pectoral, the anal fin commencing 3^ inches behind the front of the origin of the 

 ventral. It extends back for 2| inches along the inferior margin of the fish, but is 

 not perfect posteriorly ; the front part is also truncated at the distance of one inch from 

 its origin, so that its depth cannot be seen. Judging, however, from the stoutness of the 

 rays of the front part, the anal fin must have corresponded pretty closely in shape and 

 size with the dorsal. The latter is situated pretty well opposite the interval between the 

 ventrals and anal ; but, as so comparatively short an interval occurs between the ventral 

 and the pectoral, it seems placed much further forwards than is usually the case in this 

 family of Ganoids. This dorsal fin is large and powerful, triangular in shape, very high 

 in front, the anterior rays rising fully 3 inches from the margin of the body, and its base 

 extends to about the same length. Unfortunately in this specimen the posterior rays are 

 much injured ; in No. 6, however, the greater part of the fin is well displayed. As 

 regards the caudal fin, No. 4 (PI. Ill, fig. 12) shows the greater part of both lobes, and 

 must have belonged to a fish of about the same bulk as the headless and tailless body 

 No. I . It is completely heterocercal, deeply cleft, and evidently considerably inequilo- 

 bate ; both lobes must have been very powerful, although, their ends being truncated, 

 their actual length cannot be determined. All these fins are composed of very numerous 

 closely set rays ; the demirays in the anterior part of each fin imbricating over each other 

 from before backwards, and exquisitely ornamented on their shining ganoid surfaces with 

 fine longitudinal, sometimes slightly oblique ridges or strise. Towards their extremities 

 the rays dichotomise repeatedly, and end in exceedingly fine ramifications. They are also 

 divided by closely placed transverse articulations ; the joints being nearly square in all the 

 fins save the caudal, where, by the closeness of the articulations, they are much broader 

 than deep. All the fins are likewise set along their anterior edges with very fine fulcral 

 scales, so small indeed as to require a lens to distinguish them, notwithstanding the large 

 size of the Fish. 



Some evidences of internal skeleton are also visible. In No. 1 a line of much 

 mutilated spinous processes may be traced along the middle of the Fish ; but there is no 

 evidence of vertebral bodies or of ribs. Remains of strong interspinous bones may be 

 seen supporting the anal fin, the anterior of these measuring at least 1^ inch in length; 

 those directly supporting the dorsal are short, but in specimen No. 2 there is also 

 evidence of a deeper set, following on their proximal extremities, and interposed 

 between them and the spinous processes. All these internal bones are in the fossil 



