REPORT ON THE DEEP-SEA FISHES. 221 



which is nearly two-ninths of the total length, without caudal ; eye one-half of the length 

 of the head ; interorbital space flat, about two-thirds as wide as the eye ; snout short, 

 with rather oblique upper profile. Mouth narrow, hardly lateral, its cleft being above 

 the level of the lower margin of the eye. Gill-opening as in Bathylagus atlanticus, but 

 the branchiostegal membrane is not so muscular across the isthmus as in that species. 

 The origin of the dorsal fin is nearer to the end of the snout than to the end of the caudal 

 fin. All the fins are composed of feeble rays. The vent is situated at the beginning 

 of the posterior third of the total length and the anal commences immediately behind 

 it. Pectorals rather narrow, close to the lower profile. Ventrals opposite to the middle 

 of the dorsal fin. 



Otherwise the. specimen is so much damaged, that I can only add that its scales and 

 coloration seem to have been very much the same as in the Atlantic species ; and that it 

 is altogether a rather more slender fish. 



Habitat. — One specimen, 4^ inches long, was obtained in the Antarctic Ocean, 

 Station 157, at a depth of 1950 fathoms. 



Family Raih y thrissid.e. 



Body oblong, with rounded abdomen, covered with cycloid scales ; head naked ; 

 bjarbels none. Margin of the upper jaw formed by the intermaxillaries mesiaUy, and by 

 the maxillaries laterally. Opercular apparatus complete. Adipose fin absent ; dorsal fin 

 much elongate, many-rayed ; anal fin short. Stomach with a blind sac ; pyloric append- 

 ages numerous. Gillr apparatus well-developed ; pseudobranchi^ ; gill-openings wide ]J 

 an air-bladder. Ova very small ; ovaries without duet. 



The fish for which I propose this new family differs from the Clupeidfe and allied 

 forms chiefly in the development of the dorsal fin. 



Bathythrissa. 



Bathytlirissa, Giinth. Ann. and Mag. Nat. Hist., vol. xx., 1877, p. 443. 

 Pterothrissus, Hilgendorf, Act. Soc. Leop. Carol., xiii. p. 127.' 



Body covered with scales of moderate size ; head narrow, oblong, with the muciferous 

 channels much developed. Eye large. Mouth narrow, Coregonoid, with liands of minute 



' Dr. Hilgendorf .seems to claim priority for the name proposed by him. To this I must demur, until he brings 

 forward more satisfactory evidence as to the date of publiaition of the sheet of the Leopoldina, which contiiins his first 

 notice of this fish. That sheet, indeed, bears " August " on the first page (p. 113), but as the Manuscript of it was finished 

 only on the 31st of that month (see p. 128), it is evident that it could not have been printed, much less published in that 

 month. Neither the German nor the English reporters on the ichthyological literature of the year 1877 mention Dr. 

 HilgendorPs paper, which would hardly have escaped their notice if that part of the Leopoldina had been actually 

 issued. The exact date of the publication of Bathythrissa is November 1. 



