TINS OF GANOIDS AT!fD TELEOSTS. 557 



the corresponding segment o£ the second radial element. The 

 first radial element is related to four fin-rays, of wMch the first 

 three are but feebly developed. The first ray simply rests on 

 the anterior margin of the distal end of the proximal segment ; 

 but the second, third, and fourth, tbe last mentioned being the 

 ray strictly belonging to tbe first radial element, articulate with 

 the three pairs of sockets on tbe distal segment. 



Anterior to the first ray-supportiog radial element there are 

 seven flattened lamellar bones extending forwards nearly to the 

 supraoccipital spine, and apparently representing a series of 

 vestigial proximal radial segments which have lost their fin-rays. 



Anal fin. — This fin in all essentials very closely resembles the 

 dorsal fin, except for tbe larger number of radial elements (viz., 

 twenty-five) aud fin-rays (viz., twenty-eight). This distal segment 

 of the first radial element is, however, apparently double. 



CLTJPEIDJi:. 



Olupea harengus. 



Dorsal fill. — In this species the eighteen fin-rays of the dorsal 

 fin are supported by a corresponding number of radial elements. 

 All the radial elements are very similar, and each consists of a 

 proximal and a distal segment, the former having a well-marked 

 postero-superior process. No distinct mesial segments could be 

 detected. The nodular distal segments are simply clipped by 

 tbe cleft bases of the various dermal rays. In front of the fircit 

 ray-bearing radial element there is a series of about eighteen 

 slender vestigial proximal segments extending forwards at regular 

 intervals to the skull. 



Anal fin. — There are fifteen radial elements, all of which are 

 very similar to those of tbe dorsal fin, aud seventeen fin-rays. 

 The first radial element supports two fin-rays, of which the 

 second clips the distal segment. The last radial element is also 

 related to two fin-rays supported by its distal segment, 



GrTMNOTID^. 



Gymnotus electricus. 



The dorsal fin is entirely absent. 



Anal fin. — The long anal fin of this species is supported by an 

 equally extensive series of radial elements. The latter (Pi. XXII. 



