574 PEOF. T. W. BEIDGE ON THE MESIAL 



the last two fiu-rays, the first has the normal relations to the last 

 radial element, but the second merely embraces the hinder margin 

 of the postero-superior process. 



It is worthy of note that, owing to the suppression of the distal 

 segments of the various radial elements, each fin-ray is solely 

 supported by its secondary connexion with the element immedi- 

 ately posterior to that to which it rightly belongs. 



Anal fin. — The anal fin is altogether more normal in the 

 structure and relations of its radial elements, of which there are 

 forty-five, supporting an equal number of fin-rays. All the 

 elements (PI. XXIII. fig. 32, r.e.) have well-developed distal {d.s.) 

 in addition to proximal (p.s.) segments, and the position and re- 

 lations of the former are such that each is supported partly by the 

 corresponding proximal segment, and partly also by tliat pertain- 

 ing to the next succeeding element. The distal segments are 

 apparently ossified from two lateral centres, and in the specimen 

 examined, which was about two and a half feet in length, were still 

 separated by an intervening tract of cartilage. 



All the fin-rays are cleft proximally and embrace the distal 

 segments of their supporting radial elements. 



Labeid^. 



Fseudoscarus superhus. 



Dorsal fin. — There are eighteen radial elements and nineteen 

 fin-rays. The first eight of the series of radial elements (PL XXIII. 

 fig. 33, r.e^-r.e?) are all unisegmental, consisting only of proximal 

 segments (j).s.)- Each proximal segment is more or less dagger- 

 shaped, with a short and nearly vertical postero-superior process, 

 as in AnarrJiicJias. At its distal extremity a slender bar of bone 

 passes from the base of the postero-superior process, and, 

 curving downwards and forwards, fuses with the anterior margin 

 of the segment in such a way as to form the outer half of a 

 bony chain- link. The ninth proximal segment (r.e.", p.s.) difi"ers 

 from the preceding in the greater length and oblique backward 

 prolongation of its postero-superior process, and also in the fact 

 that it possesses an osseous distal segment {d.s.) for the support 

 of the first soft ray in addition to the more anteriorly placed 

 " chain-link " for the last of the spinose rays. The remaining 

 elements are essentially similar to the ninth, although they have 

 no " chain-link " and gradually decrease in size. Behind the 



