246 DR. A. gCisther on a new deep-sea fish. [Apr. 1, 



by the true Ribbon-fishes {Ti-achypteridce). Tlie fish described here, 

 however, approaches the llibbon-fishes in ))Ossessinp; the characteris- 

 tics of bathybial organization in a somewhat higher degree : the 

 hones of the head are thinner, more deeply sculptured, more flexible, 

 and the muscular system is less developed than in L. cepedianiis ; 

 on the other hand, the vertebrae are firmly united by hgamentous 

 tissue. 



I take great pleasure in naming this interesting fish after Mr. 

 Fisk, to whom we are indebted for so many additions to our know- 

 ledge of the Fauna of South Africa. 



LoPHOTES FiSKf. (Platcs XIX. & XX.) 



The body of this fish is very elongate and strongly compressed like 

 that of a Regalecus ; it is nearly of uniform depth throughout, and 

 gradually narrowing in its posterior fourth. It is impossible to say 

 whether it possesses a separate caudal fin or tapers into a point, the 

 extremity of the tail being mutilated. As in the other species of the 

 genus, the vent (Plate XIX., v.) is at a short distance from the ex- 

 tremity of the tail, but no anal fin can be made out, possibly on account 

 of the mutilation of this part. The head is scarcely deeper than the 

 body, strongly compressed ; its upper part forms a low crest which is 

 prolonged forward into an extraordinary sword-shaped process which 

 projects far beyond the snout. Like the other bones of the skull, this 

 process is flexible and deeply longitudinally sculptured ; thin as the 

 blade of a knife, it is sharp-edged above and below. The dorsal fin 

 commences on the extreme point of this process with an extremely 

 long and compressed ray. I am unable to give the exact length and 

 form of this ray, as only a fragment about as long as the head i-emains ; 

 probably when complete it was three or four times that length and 

 may serve either as a tactile or an attractile organ. It is conuected 

 with the following rays by membrane ; these are not of unusual 

 length, b>it the succeeding rays, which are attached to the upper edge 

 of the cephalic process, are short and widely set. From above the 

 eve the rays become longer again, forming a fin which is about half 

 as deep as the body underneath, and which is continued to the end 

 of the tail. 



To return to the description of the parts of the head, we notice, 

 in the first instance, the large eye, which is longer than the snout and 

 possesses a transversely oval pupil. The mouth is rather small, 

 obliquely ascending forward and with its cleft extending backwards 

 to below the anterior margin of the eye. The maxillary is elongate, 

 lamelliform, broader than the suborbital ring, which consists of two 

 bones only. Both jaws are armed with a series of small uncinate 

 teeth laterally, which series become double anteriorly. The oper- 

 cular bones much dilated and overlapping each other. 



Gills well developed, a short slit behind the fourth arch. Six 

 brauchiostegals. The pectoral fin consists of thirteen rays, inserted 

 on a broad horizontal base, and [)oints upwards. 



The skin is scaleless and contains a rather thick deposit of a silvery 

 pigment, which in some parts assumes a blackish hue, and seems to 



