REPORT ON THE PELAGIC FISHES. 



Sea Fishes (Zool. Chall. Exp., pt. Ivii. p. 35). I have there stated the reasons which lead 

 me to believe that it was captured near the surface, and not at the depth of 2675 fathoms 



to which the dreds:e descended on that occasion. 



Lepidopus tenuis, Gthr. 



Lepidojms tenuis, Giinth., Zool. Chall. Exp., pt. Ivii. p. 37, pi. vii. fig. B. 



On the passage from the Sandwich Islands to Tahiti, at Station 271, in lat. 0° 33' S., 

 long. 151° 34' W., a young Trichiurid, 95 mm. long, was obtained. The trawl had been 

 at a depth of 2425 fathoms, but it is probable that this small and delicate fish was swim- 

 ming near to the surface when it got entangled by the trawl. Although there cannot be 

 any doubt as to this specimen being a young Lepidopus, it is too much injured to enable 

 us to say whether it should be referred to Lepidopus tenuis or Lepidopus elongatus, 

 if, indeed, these fishes are specifically distinct. Neither is the place of its capture a 

 guide for its specific determination, Lepidopus tenuis having been found in the 

 Japanese Sea, and Lepidopus elongatus ofi" New Zealand and in the North- Western 

 Atlantic. 



Thyrsites prometheus, C. V. (PI. I. figs. C, D). ■ 



Of the two small fishes here described and figured, the smaller, which is 5 mm. long, 

 was obtained on June 17, 1875, south of Yeddo, and the larger, of double the size, five 

 weeks later, namely on July 23, 1875, north of the Sandwich Islands. 



The specimens are not in a good condition, having been placed at the time of their 

 capture on a microscopic glass-slide ; the sides of the head have been much crushed, 

 so as to render the outlines of its constituent parts indistinct, more especially the 

 opercular and scapular portions, which, therefore, could not be delineated in the 

 figures. 



The specimens are evidently not far removed from the embryonic condition ; and 

 Liitken's excellent account * of the developmental stages of Nealotus and Gempylus can- 

 not leave us long in doubt as to the family of fishes to which our specimens should be 

 referred, especially not, if, as I am still inclined to think, the caudalless and caudate 

 Trichiuridaj be retained in the same family. The embryonic stage of the individuals is 

 apparent from the pointed diphycercal termination of the vertebral column which is 

 surrounded by a circular membrane out of which the caudal fin is developed ; in both 

 specimens the caudal rays are visible as extremely fine striae. In the larger specimen 

 (fig. C) a series of seven or eight haemal apophyses has been developed in this portion of 



> K. dansk. Vidensk. Sekk. Skriv., xii., 1880, p. 448 et seq. 



