FINS OF GANOIDS AND TELEDSTS. 571 



proximal segment suturally joined to the penultimate one. The 

 first radial element supports two rays, and the last also two. 

 The distal segments of the first two radial elements have incipient 

 " chain-link " artit:ulaiions with the second and third rays, as in 

 the second dorsal fin. 



COTTID^. 



Trigla gurnardus. 

 Dorsal fin. — This fin consists of a continuous series of twenty- 

 nine radial elements supporting anteriorly eleven spinose rays and 

 posteriorly nineteen soft, flexible, but unbranched rays. The first 

 ten radial elements (PL XXIII. fig. 29) are unisegmental, consist- 

 ing of proximal segments (p.s.) only. Each proximal segment is 

 produced into a postero-superior process which is provided with 

 well-developed lateral wings for the enclosure of a section o£ the 

 medio-dorsal groove (fig. 29). The wings are somewhat con- 

 tracted at their origin, but expand distally so as to overlap in an 

 imbricated fashion the similar wings of contiguous segments, 

 and, in consequence, the usual clefts between them for the 

 transmission of the depressor and elevator muscles of the spines 

 become converted into complete foramina {f). At the distal 

 end of each proximal segment, near its anterior margin, there are 

 two articular facets, one {fc}) for articulation with the hioder 

 margin of the postero-superior process of the proximal radial 

 segment in front, and a second {fc^), situated immediately in front 

 of the first, for articulation with the condylar base of a spine. 



The eleven spinose rays have imperforate bases terminatiug iu 

 a transversely elongated condyle, and in the absence of distal 

 radial segments each spine is supported solely by the facet oa 

 the proximal segment immediately behind that to which it 

 properly belongs. The second spine is that which strictly belongs 

 to the first radial element, the first really belonging to an 

 anterior suppressed element. The eleventh element supports the 

 eleventh spine, in addition to the first of the series of flexible 

 rays. The last three spines are more or less vestigial, and hence, 

 externally, there is an apparent interruption in the continuity of 

 the spinose and soft sections of the fin. 



The remaining nineteen radial elements are precisely similar 

 to those of the anterior portion of the fin except that they all 

 possess nodular bony distal segments, which have the usual 

 articulation with their own proximal segments and also with 



