REPORT ON THE DEEP-SEA FISHES. 131 



space of greater width and less concave than other specimens, the width being two-thu-ds 

 of the diameter of the eye; the posterior limb of the prseopereulum is much more oblique, 

 whilst in the other specimens it is almost vertical. The scales of the Greenland 

 specimens are much more smooth, and in one of them only a few of the scales show traces 

 of the lateral keels. The scales are roughest in our specimens from Finmarken, and they 

 scarcely possess a scale which does not show lateral keels or spines. The length of the 

 pectoral fin is subject to great variation; in the Finmarken specimen it is short, contained 

 twice and one-fourth in the length of the head; in the New England specimen long, and 

 contained once and four-fifths in the length of the head, the Greenland specimens being 

 intermediate in this respect. 



Macrurus rudis (PL XXVII. ). 



Coryphmnoides rudis, Giinth., Ann. and Mag. Nat. Hist., 1878, vol. ii. p. 24. 

 D. 10 I 94. A. 96. P. 19. V. 10. 



Snout obtusely conical, projecting beyond the mouth, which extends backwards to 

 beyond tlie middle of the eye. The outer series contains stronger teeth in both jaws. 

 Barbel about as long as the eye. The 2:)rofile of the nape ascends very slightly towards 

 the dorsal fin. Scales equally rough over the whole of their surface, the spinelets being 

 subequal in size, densely packed, and not arranged in series. There are eight scales in a 

 transverse series between the first dorsal and the lateral line. Anterior margin of the 

 second dorsal spine armed with barbs placed at some distance from each other. The 

 second dorsal fin commences at a distance behind the first scarcely inferior to the length 

 of the base of the first. The outer ventral ray produced into a long filament. 



Habitat. — Pacific, north of the Kermadec Islands, Station 171; depth, 600 fathoms. 

 Three specimens, 3 inches, 11 inches, and 33 inches long. 



Pacific, north of the Kermadec Islands, Station 170a; depth, 630 fathoms. Three 

 specimens, 6 to 7 inches and 12 inches long. 



Pacific, north of the Kermadec Islands, Station 170; depth, 520 fathoms. Two 

 specimens, 3^ inches long. 



As in other fishes, so in Macrurus, the eye is comparatively larger in young than in 

 adult individuals. In our large examj^le the head is 175 mm., the eye 25 mm., the snout 

 43 mm., and the width of the interorbital space 50 mm. These dimensions being in the 

 smaller respectively 50, 16, 15, and 13 mm. 



Also the serratui-e of the dorsal spine changes with age, the biU'bs being widely set 

 and few in number (seven) in very young specimens 6 inches long (fig. c), much more 

 numerous (twenty) in older examples 11 inches long (fig. h), and becoming rather 

 obsolete in adult ones. 



