6 Messrs. Hancock and Embleton on a Gymnetrus 



dorsal fin and not a separate structure, though it is probable 

 enough that the ends of its rays may have been for some distance 

 free and even furnished with a membrane on their posterior mar- 

 gin widening to the top, giving them the appearance of peacocks' 

 feathers as asserted by the fishermen. This probability is height- 

 ened by the fact of the head of the Gymnetrus from the Cornish 

 coast being provided with two long rays having broad membra- 

 nous expansions at their ends, which would justify a casual ob- 

 server in comparing them in form to the above feathers. It is 

 not unlikely besides that the second, third, fourth and fifth rays, 

 on account of their resemblance in delicacy to the ordinary fin- 

 rays, may have terminated differently from the rest. The rays 

 having been broken, we cannot say of ourselves whether they 

 were uniform in size or not ; but from what we have learnt by 

 questioning those who saw the fish, we conclude that the middle 

 rays were the longest, those in front and behind them gradually 

 decreasing in length. The rays of the crest are more closely set 

 generally than those of the rest of the dorsal fin, which stand 

 about half an inch apart. Exclusive of the crest there are 268 

 rays in the dorsal fin. They terminate in fine points that pro- 

 ject a little beyond the margin of the very delicate connecting 

 membrane. This membrane was colourless according to the 

 fishermen, but was bordered by a pale red when we observed it. 

 The rays of the back are highest about the middle of the fish, 

 where they measure upwards of 3|^ in., and at the termination of 

 the fin are about 1 in. in height. 



From the end of the fin the dorsal margin slopes rather rapidly 

 downwards to within about an inch of the ventral margin, and is 

 then prolonged to a rounded point at the caudal extremity. There 

 is no caudal fin. The skin at this part, it is true, was broken, but 

 on pressing together the broken edges they seemed to leave no 

 hiatus. The fishermen persisted that the part was at first entire, 

 and that there was no appendage whatever. At a distance from 

 this point of about 2 inches along the ventral margin there exists 

 a shallow notch. Both the margins of the fish at this part are 

 very thin. On carefully inspecting the surface of the body, some- 

 thing like a series of transverse marks corresponding to the 

 bodies of the vertebrse can be discerned, and the number of these 

 has from this appearance been rQughly estimated at about 110. 



The pectoral fins are placed cto.se behind the gill-covers, and 

 much nearer to the ventral margin than to the lateral line, which 

 is at least half an inch above the points of the rays of the fins ; 

 these fins are colourless, delicate, subtriangular, and the longest 

 rays measure 2 inches. They are eleven in number and a good 

 deal arched. 



The ventral fins are represented by a pair of very strong and 



