580 PHOr. T. W. BEIDGE ON THE MESIAL 



between the distal and proximal segments is less intimate than 

 in most other Teleosts. To some extent the series of distal 

 segments articulate with the longitudinal groove on the distal 

 margin of the series of proximal segments, and a short, relatively 

 stout ligament passes from each distal segment to the subjacent 

 proximal segments ; but the articulation between the two series 

 of segments is, nevertheless, unusually mobile — in fact, the 

 connexion of the distal segments with one another is much more 

 intimate than is their relation to the series of rigidly intercon- 

 nected proximal segments. 



Each fin-ray {f.r.) is cleft basally and the two arras, which 

 terminate inferiorly in thin, plate-like expansions, and not in 

 articular surfaces, closely and firmly clip a distal radial segment. 



Anal fin. — In the anal fin there are twenty-four radial 

 elements and a corresponding number of soft fin-rays, both of 

 which in structure and in mutual relations precisely resemble 

 those of the posterior dorsal fin. 



IKonacanthus granulosus. 



As in JBalistes, this species is provided with a short spinose 

 anterior dorsal fin and a soft posterior one, in addition to an 

 anal fin. 



Anterior Dorsal fin. — Sorensen [10] has also figured and 

 described the two spines with their supports and muscles in 

 M. pardalis, to which species M. granulosus exhibits a fairly 

 close resemblance in so far as the structures in question are 

 concerned. The bony support for the spines is somewhat 

 similar to that of JBalistes capriscus, but is shallower, with the 

 two lateral foramina replaced by notches, and, as it is wholly 

 supported by the hinder part of the cranial roof, the "tige apo- 

 physaire " is wanting. As in Salistes, the fin-support bears no 

 resemblance to the ordinary radial elements of the posterior 

 dorsal fin, and no suggestion can therefore be offered as to the 

 number or nature of such elements, or their segments, which 

 enter into its formation. 



Posterior Dorsal fin. — This fin is very similar to the corre- 

 sponding fin in Balistes, and consists of twenty-eight or twenty- 

 nine radial elements and a corresponding number of soft rays. 

 The proximal radial segments are firmly connected with one 

 another by squamous sutures, and also with the subjacent neural 



