"FINS OP GANOIDS AND TELEOSTS. 539 



the dermal fin-rays, which is so characteristic a feature in the 

 lower types, is altogether wanting in Amia. In tHe latter fisli 

 the two are numerically identical, each of the forty -nine radial 

 elements having only a single fin-ray, and this appears to be the 

 typical relation of the two series of structures in all the higlier 

 Pishes. 



Anal fin. — In the anal fin eleven radial elements support a 

 corresponding number of soft fin-rays. The radial elements are 

 very similar to those of the dorsal fin, both in structure and 

 mutual relations. All are trisegmental except the first two, the 

 first consisting only of a proximal segment, and the second, in 

 addition, of a nodular cartilaginous distal segment. The mesial 

 segments of tbe third and fourth, and those of the tenth and 

 eleventh, and the distal segments of all the radial elements are 

 cartilaginous. 



It would seem that both the anal and dorsal fins are liable to 

 individual variation as regards the precise number of their radial 

 elements. In the specimen described and figured by Franque 

 [7] there were apparently fifty-three elements, including the 

 vestigial rayless one which, as in my specimens, lies immediately 

 behind the last ray-supporting element, and fifty-three dermal fin- 

 rays. The proximal segments of the first and second are figured 

 as if fused together, which was certainly not the case in the 

 specimens I have examined. Shufeldt [8] also mentions fifty- 

 three as the number of radial elements in the specimens he 

 examined. The anal fin is figured by Franque (Z. c.) as having 

 twelve radial elements, and this seems also to have been the case 

 in Shufeldt's specimens. 



It may be remarked that both Franque and Shufeldt over- 

 looked the presence of the distal series of segments in both the 

 anal and dorsal fins. The latter writer, for example, in referring 

 to the fin-rays of the dorsal fin says, " These rays are supported 

 by an equal number of interspinous bones, through the inter- 

 vention of little ossicles that pass obliquely from one to the 

 other" {I.e. p. 85). The "little ossicles" are the mesial 

 segments, the so-called "interspinous bones" being the struc- 

 tures which I have termed proximal segments, but no reference 

 is made to the series of distal segments. Franque {I. c.) also makes 

 a similar omission, although he has quite correctly figured the 

 shape and mutual relations of the proximal and mesial segments. 



Shufeldt {I. c.) figures and describes five " delicate little 



