576 PROF. T. W. BRIDGE ON THE MESIAL 



extended basal condyle fitting into a corresponding groove. 

 The base of the third spine is perforated by a foramen, into 

 -which projects the contracted hinder end of the distal segment 

 of the same element. The soft rays immediately behind the 

 last spine have " peg-and-s octet " articulations with the distal 

 segments, but the more posterior rays simply embrace those 

 segments in the usual manner. The distal segment of the last 

 radial element supports the last two rays, the second of which 

 probably belongs to the vestigial element. 



LabricJitJiys tetrica. 



This species very closely resembles the preceding in the 

 character of its radial elements, aud also in the mode of articu- 

 lation of the fin-rays to their supporting elements. Anterior to 

 the first of the ray-bearmg series there is a vestigial element, iu 

 addition to one behind the last of the series. 



FiSTULAEIIDai. 



Aulostoma chinense. 



Anterior Dorsal fin. — The continuous anterior spinose section 

 of the dorsal fin of other Aeanthopterygii is represented in 

 Aulostoma by a series of eleven slender isolated spines, supported 

 by a corresponding number of similarly isolated radial elements. 

 Each radial element consists only of a proximal segment, which 

 is transversely grooved at its distal end for articulation with a 

 similarly modified condyle furnished by the uncleft base of a 

 spinose ray. The various segments are almost horizontally 

 disposed, the proximal extremity of each being directed forwards. 



Posterior Dorsal fin. — In this there are twenty-five radial 

 elements and twenty-seven soft fin-rays. All the radial elements, 

 except the last two, are bisegmental, consisting of both proximal 

 and distal segments, the former having well marked postero- 

 superior processes, and both having the usual relations for 

 mutual support. The last two of the series have a single large 

 distal segment between them, and this supports four fin- rays. 

 All the remainder support each a single fin-ray. 



Anal fin. — This fin very closely resembles the posterior dorsal 

 in all essential features. 



