108 



(3) the mouth is much larger, the maxilla reaching almost to the posterior 

 border of the orbit : 



(4) the scales of the head have from 3 to 8, those of the body have 8 or 9, 

 strongly -radiating serrated crests; and there are 4 or 4- rows of scales between 

 the last ray of the first dorsal fin and the lateral line : 



(5) the interval between the two dorsal fins is longer than the base of the 

 first : 



(G) the pectorals are decidedly shorter than the postorbital portion of the 

 head, and the prolonged first ventral ray does not reach to the anal fin. 



There are about 40 long pyloric caeca, and there is a thin- walled air-bladder. 



Colours : dark stone-grey ; fins and gill-membranes black. 



Length 19 inches. 



Arabian Sea, 719 fathoms. 



Reffd. No. 13472. 



■^£> v 



Subgenus Maceueus, Gthr. 



Mouth small or moderate, entirely inferior, the infraorbital ridge distinct. 

 Teeth in bands in both jaws. Scales imbricate with spines or serrated keels : 

 no series of enlarged dorsal scales. Dorsal spine serrated. 



The following key is substituted for that given by me in J. A. S. B. Vol. 

 LXIII. pt. 2, 1894, pp. 126-127, which was reprinted by Goode and Bean in 

 Oceanic Ichthyology, p. 532. 



Key to the Indian species of the subgenus Macrurus. 



I. Seven branchiostegals : vent between the ventral fins: — 



1. Eight rays in the ventral fin : — 



i. Scales with strong serrated (parallel) ridges: barbel hardly 



half as long as the eye ... ... ... ... M. investigatoris. 



ii. Scales with spinelets : barbel at least as long as eye ... M. J'etersoni. 



2. Ten rays in the ventral fin : scales with densely packed spinelets M. nasntus. 

 :>. Eleven or twelve rays in the ventral fin : — 



i. Length of the head about a fifth of the total : — 



a Scales witli about fifteen series of capillary spinelets M.semiquincunciatus. 

 h. Scales with about seven series of capillary spinelets M. polylepis. 

 ii. Length of head about an eighth the total: scales with from 



three to eight (usually six) series of short spinelets ... M. pumiliceps. 



II. Six brancliiostegals : vent immediately in front of the first ray of the 

 nnal fin : — 



1. Seven lays in the ventral fin ... ... ... M. Hextii. 



