EEPOKT ON THE PELAGIC FISHES. 39 



Body elongate, rather compressed, naked, with black (phosphorescent) spots. Cleft 

 of the mouth very small. Eye of moderate size. Dorsal fin short, opposite to the 

 space between ventrals and anal ; adipose fin none ; anal short ; caudal emarginate. 

 Gill-openings wide. 



An atfinis Microstomati 't 



Halaphya elongata, n. sp. (PI. VI. fig. C). 



The general form of the body and the position of the fins will be seen from the 

 figure. The specimens are perfectly transparent and of the same white colour which the 

 Leptocephali assume after immersion in spirits. No scales can be discovered on any part 

 of the body. A series of minute specks of black pigment runs along the intermuscular 

 line of the side of the body, and similar specks occupy the upper and lower margins of 

 the free portion of the tail. These pigment spots remind us of similar organs in the 

 Leptocephali, and many young Scopelids. The snout is obtuse, with a narrow trans- 

 verse anterior mouth. The gill-openings are wide, the gill-membrane being grown to the 

 isthmus anteriorly for a short distance only. Pectorals well developed ; ventrals shorter. 

 A very distinct fold of the skin runs from the pectoral .along the median line of the 

 abdomen to the vent. Dorsal and anal fins of moderate height, with the rays well 

 developed. D. 12. A. 9. Caudal emarginate behind. 



Prymnothonus (PL V.). 



In the Ichthyology of the Voyage of the " Erebus " and " Terror," Richardson figured 

 a small fish which he named Prymnothonus hookeri, and which was known to him from 

 a sketch only, drawn by Dr. Hooker from the fresh specimen. He could not add any 

 further information, the notes made at the time by Dr. Hooker having been mislaid, but 

 he says that the specimen measured 1^ inches in length. It had perished before the 

 collection reached Sir John Richardson's hands. Although I applied again after the 

 return of the Challenger for further information to Sir Joseph Hooker, he was unable 

 to recollect any particulars as regards the capture of the specimen, or the circumstances 

 under which it was obtained. 



The Challenger collection contains three specimens which evidently belong to the 

 same kind of larval form, for such Prymnothonus proves to be. These specimens are 

 not in a good state of preservation, and as they are unique, only a portion of their 

 structure can be ascertained. 



The smallest of the specimens (PI. V. fig. A), was obtained in the North Pacific, on 



