pins of gaifoid9 a>'d teleosts. 577 



Ctclopteeid^. 

 Cyclopterus lumpus. 



Dorsal fin. — The hinder dorsal fia o£ this species, corre- 

 sponding to the non-spinose portion of the dorsal fin of other 

 Acanthopterygii, consists of ten soft rays, supported by an equal 

 number of radial elements, all of which are bisegmental. The 

 proximal segments of tlie radial elements are nearly straight, or 

 at any rate are so slightly angulated at their distal extremities 

 as to present only slight traces of postero-superior processes. 

 The distal segments are small nodular ossicles. The connexion 

 of the distal and proximal segments of the same radial element, 

 and with those of contiguous elements, is loose and ligamentous, 

 and there are no articular relations between the different elements 

 for mutual support. 



The basal ends of the cleft fin-rays are rugose and without 

 basal articular surfaces : their cleft proximal extremities embrace 

 the distal radial segments. 



Anal fin. — This fin is precisely similar to the dorsal. 



Teachtpteeid^ . 

 Jtegalecus argenteus. 



From Parker's description and figures [1] of the dorsal fin of 

 this species, it would seem that the supporting radial elements 

 are bisegmental. Except for a short distance anteriorly each 

 proximal radial segment is Y-shaped, consisting of an anterior 

 and a posterior arm, and a stem. The posterior arm is apparently 

 the equivalent of the postero-superior process of other Teleosts, 

 but the anterior arm is, so far as I am aware, peculiar. The 

 segments are so arranged in longitudinal series that the distal 

 extremity of the anterior arm of one abuts against the extremity 

 of the posterior arm of the segment immediately anterior, while 

 between the two, aud supported to an equal extent by both, is 

 the distal radial segment, clipped by the cleft base of its fin-ray. 

 In the more anterior elements the two arms become merged in a 

 single triangular plate. The first five proximal segments are 

 partially fused and otherwise modified to support the fin-rays of 

 the characteristic head-crest of this species. 



There is no anal fin. 



JjTSrS. JOTJEN. — ZOOLOGY, TOL. XXT. 46 



