414 DEEP-SEA FISHES OF THE ATLANTIC BASIN. 



contained 2:5- times in tlie length of tlie head. The barbel is slightly longer than the eye. 

 The snout is onc^iuarter as li)iig as the head and equal to the interorbital space. 



It differs also in the serrature of the second dorsal spine, and its length, which is 

 uearly equal to, if not longer than the head. In our niutilated specimens the first branched 

 ray is nearly as long as the head. The gill rakers are rudimentary, there being 11 below 

 tlic angle of the first arch. 



The types of this species are small and in very bad condition, making it difficult to 

 determine the dentition with certainty, but the intermaxilla has an outer series of enlarged 

 teeth and behind a villiforni band of smaller teeth. The mandibulary teeth are uniserial, 

 all small and unequal in size. The gill juembrane is attached to the isthmus, but has a 

 narrow, free margin behind. The scales are studded with minute spines, but have no 

 median keel. The intermaxilla is protractile almost in a vertical direction; it is a 'oug 

 bone, being continued beyond the vertical expansion. 



D. I, 10; the long second ray coarsely serrated. 



A single specimen, 141 millimeters in length, was obtained by the Blal'e from station 

 Lxxxiii, off' Granada, at a depth of 164 fathoms. The Alhatross secured an individual 

 from station 2474, in 44° 28' 30" N. lat., 57° 10' 45" W. Ion., at a depth of 133 fathoms; 

 and two small specimens, 154 and 203 millimeters in length, respectively, from station 2310, 

 in 35° 44' I^. lat., 74° 51' W. Ion., at a depth of 132 fathoms. 



CHALINUEA LEPTOLEPIS, Gunther. 



Voryphanoides Icptolejiw, Gunther, Ami. and Mag. Nat. Hist., 1877, XX, 441. 

 Maa-tirus (ChaUnurve) leptolepis, Gunther, Challenger Report, xxii, 144, pi. xxxi. 



Uead compressed. The snout is rather long, but its front projects but slightly beyond 

 the mouth, which is almost anterior. The eye is comparatively small, rather more than 

 one-half the length of the snout, or one-seventh the length of the head and three-fifths the 

 width of the interorbital space. Mouth wide, lateral, extending to below the hind margin 

 of the eye. The teeth of the outer series of the upper jaw are widely set and much stronger 

 than tliose of the villiform band. Mandibulary teeth in a single series. Barbel as long as 

 the eye. The preoperculum with the hind margin excised, and with the angle rounded 

 and produced backwards, naked; its lower margin is not toothed. 



Scales thin and deciduous ; most with 5 or 7 radiating keels, some, especially on the back, 

 nearly or quite smooth. There are 7 scales in a transverse series between the first dorsal 

 and the lateral line. Those on the gill-cover and in front of the ventral fins are quite 

 smooth; the front part of the snout and the lower half of the infraorbital region scaleless. 

 Second dorsal spine slightly jiroduccd, with barbs in front, which are rather distantly 

 arranged. The second dorsal fin commences at a short distance behind the first. The outer 

 ventral ray produced into a long filament. Distance between vent and isthmus equal to 

 the length of the head. 



Eadial formula: D. 19; V. IS; V. 0. 



A single specimen was obtained by the Challenger off the coast of Brazil in 350 fathoms. 



OPTONURUS, Gunther. 



Optoniirus (as subgenus), Gunther, Challenger Report, xxii, 147. 



A genus or subgenus ot 3Iacrurida', distinguished from Chalinura chiefly by the absence 

 of denticulations from the first dorsal spine. The only species as.signed by Gunther to this 

 group is O. (lentivKlatu.s (Tiichardson), which occurs in moderately deep water off the coasts 

 of South Australia and New Zealand. The Challenger obtained it oft New Zealand at a 

 depth of 275 fathoms, and off the Kermadecs, in 520 fathoms. 



MALACOCEPHALUS, Gunther. 



Malacoeephalua, Gunther, Cat. Fieh. lirit. Mns., iv, 1862, .S!)fi; Ch;illenger Report, xxil, 124, 148 (type, M. 

 lavis, Lowe). 



Intermaxillary teeth biserial, mandibulary teeth uniserial. Mouth lateral; snout short, 



