FINS or GANOIDS AND TELEOSTS. 575 



eighteenth, to the proximal segment of which it is suturally 

 attached, there is a small osseous nodule which apparently repre- 

 sents an additional vestigial element. 



The niae spinose rays have perforate bases for articulation by 

 " chain-links " with the first nine of the series of radial elements. 

 The ten soft rays, on the contrary, have the usual cleft bases for 

 the reception of the distal segments of the radial elements from 

 the ninth to the eighteenth, inclusive. Both the ninth and 

 tenth soft rays, however, are supported by a single distal 

 segment, viz., by that belonging to the last radial element. 



The nature of the " chain-link " of the first nine radial 

 elements appears somewhat puzzling. At first sight it seemed 

 possible that it might owe its formation to the fusion of a 

 hooked distal segment of one radial element with the anterior 

 distal margin of the next succeeding proximal segment ; but it is 

 certain that no trace of any such fusion can be detected even if 

 sections be taken through the possible line of junction and 

 microscopically examined. On the other hand, it seems 

 extremely probable that the chain-link results from a further 

 extension of a modification already pointed out in the case of 

 Anarrhichas, and also in the second radial element of the anterior 

 dorsal fin of Mugil. If the hook-like process of a proximal 

 segment in these Fishes were to curve forwards and downwards 

 to a still greater extent, as the result of a further ossification 

 of the iuterossicular ligament, and eventually fuse itj front 

 with the anterior margin of the segment, we should at once 

 have a chain-link precisely similar to that of Pseudoscarus. 

 This conclusion derives additional support from the essential 

 similarity of the anterior radial elements of Pseudoscarus to 

 those supporting the entire fin in AnarrhicJias. In both genera 

 the postero-superior processes are nearly vertical, and the fin- 

 rays are supported solely by the radial elements immediately 

 posterior to those to which they rightly belong. 



Anal fin. — In the anal fin there are ten radial elements and 

 twelve fin-rays. All the radial elements are bisegmental. Behind 

 the last there is a vestigial proximal segment, without a fin-ray, 

 as in the dorsal fin. 



Of the three anterior spinose rays the first two articulate with 

 the distal end of the proximal segment of the first radial 

 element. The first spine is cleft proximally and simply clips the 

 distal margin of the segment, while the second has a transversely 



