56 THE VOYAGE OF H.M.S. CHALLENGER. 



Oneirodes eschrichtii. 



Oneirodes eschrichtii, Lutken, Oversigt K. D. Vid. Selsk. Forhandl., 1871, p. 56, tab. ii. 

 D. 1 I 1 I 6. A. 4. C. 8. 



Body short, with convex upper profile. Cleft of the mouth rather oblique;' teeth 

 of moderate and unequal size, in a single series in the upper jaw; vomerine teeth. 

 Cephalic spine about one-fourth of the total length (without caudal), with a knob at its 

 extremity which (is luminous and) bears various short tentacles. A second thick and 

 flaccid spine on the top of the back, rather longer than the first. A short conical spine 

 above each eye, and another at the posterior end of the mandible. Black. 



One specimen, 8 inches long, obtained ofi" the coast of Greenland, has been described 

 in detail by Liitken. 



Melanocetus, Gtlir. 



Head and body rather compressed ; head and cleft of the mouth enormous ; trunk and 

 tail comparatively short and small. Eyes very small. Mouth vertical, jaws armed with 

 rasp-like depressible teeth of different lengths ; vomer toothless or armed with similar teeth. 

 Skin smooth, soft, and thin. The spinous dorsal is reduced to a single filament on the 

 head. The soft dorsal and anal short. Ventrals none. Gills two and a half. 



Two species are known : — 



1 . Vomerine teeth present — M. [Melanocetus) johnsonii. 



2. Vomerine teeth absent — M. (Liocetus) murrayi. 



Melanocetus johnsonii. 



Melanocetus johnsonii, Giinth., Proc. Zool. Soc. Lond., 1864, p. 301, pi. xxv. 



„ „ Lutken, Oversigt K. D. Vid. Selsk. Forhandl, 1871, p. 74; or Ann. and 



Mag. Nat. Hist., 1872, vol. ix. p. 343. 



B. 6. D. 1 I 14. A. 4. C. 8. P. 18. 



Vomer armed with a transverse series of teeth similar to those of the jaws. Length 

 of the maxillary at least one half of the total length, without caudal. Black. 



One specimen only is known, 3j^^ inches long; it was obtained by Mr. Johnson at 

 Madeira, and had in its stomach, rolled up spirally into a ball, a Scopelus which 

 measured T\ inches in length, and 1 inch in depth. 



1 Liitken describes it as horizontal, but it is evident from the figure that the lower jaw is turned upwards 

 when the mouth is shut. 



