Fishes of the Western North Atlantic 403 



mouth about 1.3— 1.5 times as great as distance between exposed nostrils. Orbit about 

 39—43 % ^s long as distance between orbits; about ^/j as long as spiracle on young 

 specimens, but only about half as long as spiracle at maturity. Inner posterior margin 

 of spiracle with a slender tentacular structure directed outward and rearward, about 

 2.3 times as long as horizontal diameter of eye on small specimens but only about 

 half as long as eye on larger ones. Anterior margins of gill openings a double curve, 

 much as in G. micrura; the first to third (longest) about 2/3 as long as orbit on small 

 specimen (473 mm wide) and about equal to orbit on one of 1,208 mm, the fifth only 

 about 50—60 "/o ^s long as first to third gill openings; distance between inner ends of 

 first pair about 2.3—2.7 times as great as distance between exposed nostrils; distance 

 between inner ends of fifth pair about 68—73 % ^s great as distance between first pair. 

 Posterior outline of nasal curtain weakly concave along median sector, the outer corners 

 projecting rearward in rounded outlines,^^ the free edge of nasal curtain finely but 

 irregularly fringed on some small specimens, except for a narrow gap in midline, but 

 nearly smooth on others and on larger ones. Lower jaw moderately arched anteriorly 

 except along midsector where it is straight or even weakly concave, the points of altera- 

 tion of curvature marked outwardly on large specimens by more or less prominent 

 rounded knobs caused by corresponding swellings of the mandibular cartilage. ^^ 



Teeth ^g in a specimen 473 mm broad but increasing in number to about {jg in 

 a 1,208 mm specimen, perhaps to a still larger number in very large ones; close-set, 

 in quincunx or transverse series in both sexes; the bases relatively shorter anteropos- 

 teriorly and broader transversely on smaller than on larger specimens; usually one 

 moderately high conical cusp, as sharp on small specimens as on larger males, occas- 

 ionally two or three cusps (Fig. 96) ;2^ 10—12 rows in function simultaneously in each 

 jaw, perhaps more on largest examples; upper dental band occupying about 70 */o 

 of breadth of jaw, the lower a little less. 



Pelvics brush-shaped, much as in G. micrura, extending rearward beyond rear 

 limits of pectorals for a distance about as great as length of spiracle ; outer and inner 

 margins nearly straight, posterior margin weakly convex; corners moderately rounded. 

 Claspers of mature males not yet studied. 



Color. Disc usually dark brown above, with grayish or reddish cast, or coffee 

 brown, shading to cinnamon at margins; variously marked with small darker dots or 

 dark or pale spots or blotches of indefinite outline, often in a marbled pattern; some- 

 times with pale-rimmed ocellar spots; upper surface of tail of same ground color as 

 disc, marked on small specimens with pale crossbars (extensions of the pale color of 

 the lower surface), or with dark and pale bars, which are mostly lost with growth.** 



21. This is one of the minor characters in which G. alta'vela differs from G. micrura (of. Fig. 95 B with 97 A). 



22. These swellings, in the form of "hard knoblike denticles", are pictured as sharp-pointed on G. crooki of Japan 

 (Fowler, Bull. U.S. nat. Mus., 100 [ij], 1941: 455, fig. 12). 



23. The presence of occasional teeth with two cusps on one small specimen, and of a few with three cusps on a male 

 of i,2o3 mm (about 4 ft.) is evidence that the tricuspid teeth described and pictured by Rochebrune (Act. Soc. 

 linn. Bordeaux, [4] 6, 1882: 54, pi. 2, fig. 3) for his 'vaillanti cannot serve as a basis for specific separation. 



24. The tail shows these crossbars on a specimen 473 mm broad from Barnegat, New Jersey, and it is similarly described 



