Fishes of the Western North Atlantic 357 



Second dorsal fin: vertical height 3. i ; length of base 4.2. 

 Anal fin: vertical height 3.65 length of base 4.6. 

 Caudal fin: upper margin 30.3; lower anterior margin 12.4. 

 Pectoral fin: outer margin 23.85 inner margin 6.4; distal margin 17.6. 

 Distance from snout to: ist dorsal 33.O; 2nd dorsal 61.O; upper caudal 69.7 j pec- 

 toral 22.O; pelvics 49.2; anal 62.0. 



Interspace between: ist and 2nd dorsals 17.25 2nd dorsal and caudal 5.3; base of 

 anal and caudal 3.6. 

 Distance from origin to origin of: pectoral and pelvics 26.75 pelvics and anal 12.4. 



Trunk moderately stout, its height at origin of ist dorsal a little more than % its 

 length to origin of caudal. Midline of back with a low dermal ridge occupying the middle 

 % of the space between ist and 2nd dorsals in embryos 5°' whether or not this ridge persists 

 throughout life, or how regularly, is not yet known.'* Caudal peduncle moderately flat- 

 tened, upper precaudal pit well marked, subrectangular, the lower only weakly defined. 

 Dermal denticles so nearly flat that skin is smooth to the touch, overlapping only very 

 little, the skin exposed here and there, their blades broader than long, usually with 5 

 (occasionally 6 or 7) low, sharp-edged ridges, the posterior margins very broadly ovate, 

 usually with 5 very short teeth (the median only a little the largest), or in some cases 

 merely sinuous in the corresponding radii, depending on the position on the body and on 

 the degree of wear; pedicels rather slender. 



Head about Y^ of total length, its dorsal profile moderately and evenly convex, 

 about % as wide at outer ends of nostrils as at eyes. Snout thick-tipped, very broadly 

 rounded in front and noticeably short, its length in front of a line connecting outer ends 

 of nostrils a little less than '^/o as great as distance between inner ends of latter," its length 

 in front of mouth between V3 and ^^ as long as head to origin of pectoral (about 26 to 

 28%) in adult, but relatively somewhat longer in embryo. Eye approximately circular, its 

 anterior edge about opposite front of mouth, noticeably small and increasingly so with 

 growth, its horizontal width decreasing from about 40% as great as distance between 

 inner ends of nostrils in embryos to only about 20% as great as that in large speci- 

 mens. Gill openings evenly spaced, the ist 2 to 3 times as long as diameter of eye in 

 adult, but only a little longer than eye in embryo, the 5th slightly the shortest, the 3rd 

 slightly the longest, the 4th above origin of pectoral. Nostril moderately oblique, its inner 

 end nearer to mouth than to tip of snout by a distance a little shorter than diameter of eye, 

 its inner margin slightly expanded in obtusely subangular outline near inner end. Mouth 

 about twice as broad as high. 



Teeth ' '' " ti^H— T- u '^H r^ > uppers broadly triangular, the ist and 2nd nearly sym- 

 metrical, but subsequent teeth increasingly oblique, the inner margins weakly convex 



53. All the embryos listed above show this ridge more or less clearly. 



54. We did not appreciate the importance of this character at the time when we examined the adults listed above in 

 the fresh state. 



55. About 50 per cent that great as calculated in adults, 42 to 43 per cent by direct measurement in embryos. 



