224 ■ THE VOYAGE OF H.M.S. CHALLENGER. 



Alepocephalus hairdii. 



Alepoceplialus hairdi, Goode and Bean, Proc. U.S. Nat. Mus., vol. ii., 1880, p. 55. 

 B. 6. D. 22. A. 25. P. 12. V. 10. L. lat. 65. L. transv. 7 | 12. Ccee. pyl. 15. 



The height of the body is contained five and one-third times in the total length (without 

 caudal) ; the length of the head four times and one-third. Snout equal to the width of 

 the orliit, which is one-fourth of the length of the head. Snout sub-conical, with the 

 lower jaw included within the upper. Scales large, thin, oblong, triangular at the free 

 end. Teeth on the intermaxillaries, mandible and palatines. Uniform indigo-blue. 



Habitat. — One specimen, 23 inches long, was obtained on the Grand Banks, 

 Newfoundland, iij 200 fathoms. 



Alepocephalus niger (PI. LVI. fig. B). 



Alepocephalus niger, Giinth., Ann. and Mag. Nat. Hist., 1878, vol. ii. [x 248. 



B. 6. D. 21. A. 27. P. 10. V. 6. L. lat. 140. 



Scales small. The length of the head is rather less than one-third of the total 

 (without caudal) ; snout projecting beyond the mouth. Black. 



Habitat. — North of Australia, 75 miles east-south-east of Raine Island, Station 184 ; 

 depth, 1400 fathoms. One specimen, 13 inches long. 



The depth of the body is one-sixth of the total length without caudal ; the length of 

 the head rather less than one-third. Head scaleless, flat aboA'^e, the least width of the 

 interorbital space being two-ninths of the length of the head. Eye of moderate size, one- 

 sixth of the length of the head, and rather more than one-half of that of the snout. The 

 snout is depressed, broad, the intermaxillary occupying a transverse position with a sharp 

 upper edge which penetrates through the skin. The side of the mouth is formed by the 

 maxillary, which extends backwards a little beyond the front margin of the eye.' 



Intermaxillary and mandible armed with a single series of small acute teeth ; a 

 transverse series of similar but smaller teeth stretches across the fore-part of the palate ; 

 it is interrupted in the middle, opposite to the head of the vomer, which is toothless. 



As in Alepoeep)lialus rostratus the bones of the head are very thin and fragile, the 

 gill-cavity being covered by a membrane, which is supported by radiating bony ridges of 

 tiie operculum and suboperculum, not unlike the branchiostegals which are included in the 

 same membrane. 



Gills four, the laminae being short in the upper part of each branchial arch and thicker 

 isolated and vermiform in the lower part. Gill-rakers stout, pointed, rather widely set ; 

 fourteen on the outer branchial arch. 



1 The nasal region is so much injured, that the form of the nostrils cannot be ascertained. 



