290 Transactions. — Zoology, 



In the Moeraki specimen the seventh and the ninth rays are perfect (pi. 

 xxiii., fig. 1, rl, rd) : the seventh is 1 foot 5-5 inches long, the ninth 1 foot 

 3-5 inches. Both taper gradually to the distal end and terminate in a some- 

 what irregularly lanceolate or spear-head shaped lohe ahout 1 inch long hy 

 rather less than half an inch wide (pi. xxiii., fig. 2). This lobe is formed by 

 an expansion of the cutaneous covering of the bony ray, and is considerably 

 thickened and corrugated on the surface. The bony ray also tapers gradu- 

 ally to its extremity and ends in a very fine point about \ inch from the 

 end of the cutaneous lobe. 



The relative thickness of the spines corresponds very well with Hancock 

 and Embleton's description quoted above : the first ray is about f inch 

 thick at the base, the second to the fifth about -^ inch ; the sixth and 

 seventh a little more than | inch ; from the eighth to the fifteenth the 

 diameter gradually decreases. The first four, also, are closer together than 

 the rest. 



The first five spines, although broken, have evidently not lost much of 

 their length. The first is 1 foot 5-5 inches long, the second a little less, the 

 third, fourth, and fifth about 13 inches ; all the rest are broken off short. 



All the rays are connected by membrane with one another, and the last 

 is similarly connected with the first ray of the so-called second dorsal, so 

 that, as in some other specimens described, the two dorsals are continuous. 

 The membrane uniting the first four rays extends to a distance of 9 inches 

 from the base, and its edges do not appear to be perfect. In the 7th 

 (perfect) ray (pi. xxiii., fig. 2) the terminal lobe is continued proximalwards 

 by a thin membranous expansion along the posterior edge. The border of 

 this expansion is evidently unbroken to a distance of 9 inches from the ex- 

 tremity, and I think it may be assumed that, for the rest of its extent, this 

 membrane extended to the next ray. All the rays are quite smooth, pre- 

 senting no trace of the spines or hooks described in some other specimens. 



My specimen would therefore seem to show that the rays of the crest, or 

 so-called first dorsal fin, are united for about the proximal half of their 

 length by membrane, that for the rest of their extent they are fringed 

 posteriorly by membrane, and that they terminate in somewhat thickened 

 lanceolate expansions. I have no means of determining whether all termi- 

 nate in the same way, or Avhether, as in Cuvier's figure of R. gladius (pi. xxiv., 

 fig. 6), some of them simply taper to a point. One would like, by the by, 

 to know certainly whether Cuvier's figure is an exact representation 

 of the specimen for which it was taken, or whether it is in any 

 way " restored." The extreme brittleness of the rays of the crest 

 would seem to render the capture of an absolutely uninjured specimen 

 extremely improbable ; and it is therefore not unlikely that the figure in 



