Fishes of the Western North Atlantic igi 



origin of the ist dorsal, with both its branches terminating just in front of, under, or well 

 behind, the 2nd dorsal} also a ridge along midline of the back from the rear part of head 

 to 1st dorsal in some specimens, but seemingly not in others. Caudal peduncle with a pre- 

 caudal pit above but none below. Dermal denticles very small (less than i mm. broad in 

 specimen 31 ft. 5 in. long), slightly overlapping, scale-like, their blades varying in shape, 

 but usually with 3 to 5 ridges, the axial ridge very high, their margins with 3 to 7 teeth, 

 the median much the longest, on relatively high pedicels." 



Head strongly flattened above, its dorsal profile concave anterior to gill openings 

 and broadly rounded in front. No distinct snout, the mouth being at the anterior margin 

 of the head. Eye minute, its horizontal diameter less than ^ as great as length of nostril, 

 its center situated a little posterior to angle of mouth. Spiracle about as large as eye, a short 

 distance behind and above the latter. Gill openings notably large but high up on the sides 

 and widely separated ventrally, the 3rd-4th over origin of pectoral, the 2nd in front of 

 pectoral and extending below it, the 2nd and 3rd longest. Nostrils at front margin of head, 

 widely separated, the space between them about % as wide as mouth, their anterior margins 

 without barbels, but each expanded as a broad, quadrilateral lobe with rounded corners, 

 overlapping the upper lip, entirely separate from mouth but with outer end continuous 

 with upper labial furrow. Mouth very large, its width nearly as great as breadth of head, 

 transverse, hardly arched. Upper labial furrow extending so far that it joins outer end of 

 nostril,' the lower furrow hardly extending beyond corner of mouth. 



Teeth similar in the 2 jaws, minute (averaging about 1.5 mm. long in an 18-foot 

 specimen, but about 4.5 mm. in a 31-foot fish), in about 310 rows, with 10 to 15 rows 

 (average about 12 to 13) functional all along the dental band, or a total count of around 

 3,600 teeth in an 18-foot specimen (Fig. 30) and perhaps still more in larger speci- 

 mens} the rows vertical toward center of mouth but somewhat oblique toward corners} 

 each tooth with a single sharp cusp curved backward.* 



First dorsal nearly an equilateral triangle, of moderate size, its vertical height a little 

 less than Vs as great as length of head, its anterior margin nearly straight, posterior mar- 

 gin moderately concave, apex rounded, its free rear tip triangular, a little shorter than the 

 base, its origin considerably in front of origins of pelvics with the rear end of its base about 

 over rear ends of bases of pelvics. Second dorsal about V3 as large in area as ist and similar 

 in form, but with its free rear tip a little longer than its base} its origin considerably 

 anterior to that of anal. Caudal noticeably large, its posterior margin broadly concave in 

 subangular outline, its upper lobe about 22% of total length, its lower lobe about 45% as 

 long as upper, the tips of both lobes pointed, the upper without subterminal notch. Anal 

 nearly as large as 2nd dorsal and similar in shape but with shorter free rear tip, its origin 



6. See White (Bull. Amer. Mus. nat. Hist., 6i, 193 1 : 144) for account of the variation in shape of the denticles. 



7. This is shown very clearly in Barnard's (Ann. S. Afr. Mus., 30, 1935: pi. 25) photograph of a newly captured 

 specimen. 



8. For excellent photographs of teeth, see Bean (Smithson. misc. Coll., ^8, 1905: pi. 36), and White (Bull. Amer. 

 Mus. nat. Hist, 61, 1931: pi. 10, 11); for additional counts, see Mowbray (Prelim. Rep. Sci. Cruise "Nour- 

 mahal," 1933: 2). 



