122 Messrs. J. Wood-Mason and A. Alcock on 



vertical tlirough the middle of the orbit. Villiform teeth in a 

 broad band in the upper and a narrow band in the lower jaw, 

 the outer row in the upper jaw considerably enlarged. Barbel 

 a little longer than the eye. 



Gill-openings wide, the gill-membranes separate ; pha- 

 ryngo-branchial membrane partially pigmented. 



Body and head, except the glosso-hyal region, covered with 

 thin, imbricating, deciduous scales of uniform size, which are 

 spinigerous except in a small area situated immediately behind 

 the base of the first dorsal fin, where they are enlarged, 

 circular, and quite smooth. A scale from tlie side of the 

 body bears from 15 to 30 equal, distant, semierect spinelets 

 in a shallow quincuncial arrangement. There are six rows 

 of scales between the posterior border of the first dorsal Hn 

 and the lateral line. 



The dorsal fins are separated by an interval equal to at 

 least twice the basal extent of the first ; the first spine of 

 the first dorsal is rudimentary, the second, which is hardly 

 prolonged, is closely and finely serrated. The anal fin begins 

 immediately behind the vertical through the last ray of the 

 first dorsal. Pectorals narrow, pointed ; their length equals 

 that of the postorbital portion of the head. Ventrals short, 

 only a little longer than the barbel. 



The vent is situated between the ventrals immediately 

 behind their base, the intestine forming a wide loop behind it. 



Colours in the fresh state : — Head and iris silvery ; body 

 chocolate, with an underlying silvery lustre ; throat and belly 

 black ; first dorsal fin black, with white base and tip. 



Two specimens (one an adult ovigerous female), 9'5 inches 

 long, from Station 115, 188 to 220 fathoms. 



1 have named this species after Mr. Peterson, the gunner 

 of the ' Investigator/ whose unabating zeal on behalf of our 

 zoological collections led on one occasion to his getting his 

 fingers almost amputated by the dredging-wire, and on another 

 occasion to his falling overboard almost into the mouth of a 

 shark. 



Subgenus Mystaconurus, Gthr. 

 31. Macrurus lieterolepis, Alcock. 



Macrurus heterolepis, Alcock, Anu. & Mag. Nat. Hist., Nov. 1889, 

 p. 396. 



Very numerous s])ecimens of all sizes were taken at Station 

 115, 188 to 220 fathoms. 

 There are seven branchiostegal rays; the mouth-cleft 



