Fishes of the Wester ?t North Atlantic 439 



Interspace between: ist and 2nd dorsals 23.6, 25.3; 2nd dorsal and caudal 7.8, 

 7.0; anal and caudal 7.8, 7.0. 



Distance from origin to origin of: pectoral and pelvics 26.5, 27.O; pelvics and anal 

 12.0, 12.8. 



Trunk strongly compressed, its height at ist dorsal about V^ (18 to 19%) of its 

 length to origin of caudal. Back smooth, without mid-dorsal ridge. Caudal peduncle 

 about % as wide as high, the upper precaudal pit strongly developed and subtriangular, 

 lower lacking in smallest specimens examined but weakly indicated in larger. Dermal den- 

 ticles so close-spaced and overlapping that skin is mostly concealed, the blades thin and 

 moderately arched, about as broad as long, small specimens usually with 3 ridges but large 

 ones with 5 and sometimes 7 ridges extending about halfway back from the anterior mar- 

 gin, 3 to 5 marginal teeth, the median considerably the longest; pedicels very short. 



Head about Vs (37%) of length of trunk to origin of caudal, its dorsal profile 

 slightly and evenly convex from origin of ist dorsal to eyes, but concave thence forward, 

 its anterior edge very thin, very broadly expanded laterally in hammer form, with 

 outer posterior margins, outward from the neck, directed slightly toward the rear; 

 breadth at eyes about 1.2 to 1.4 times its length to origin of pectoral, and its length at 

 oculo-narial prominence between V3 and V4 its breadth, much as in diplana; anterior mar- 

 gin of head scalloped with a deep depression opposite each nostril, and with a shallow con- 

 cavity midway between latter and the median line but with the midsector evenly and 

 rather strongly convex (indented in diplana, p. 415) ; a well marked groove from nostril 

 inv/ard along anterior margin of head a little more than halfway toward the midline; dis- 

 tance from anterior corner of oculo-narial prominence to anterior edge of eye only about 

 V2 to % as great as diameter of latter (about as great as diameter of eye in diplana) ; a 

 line connecting outer ends of nostrils passes anterior to mouth by a distance about V2 as 

 great as diameter of eye, one connecting centers of eyes passes a little behind front of upper 

 jaw (through front of upper jaw in diplana), and one connecting outer posterior corners 

 of hammer passes posterior to corners of mouth by a distance about V2-% as great as diam- 

 eter of eye. Head (snout) in front of mouth a little less than Ys (about 26 to 3 1 %) as long 

 as head to origin of pectoral. Rostral cartilage usually without median hole, and wings of 

 preorbital processes without inwardly directed point on anterior margin (there is a median 

 hole and such a point in diplana). Mucous pores in median sector on oral side of head cover 

 a subtriangular or irregular area near its anterior margin (a subrectangular or dumbbell- 

 shaped area in diplana) . Eye a little broader than high and much larger relatively than in 

 tudes or tiburo, its horizontal diameter about Vs as long as head in front of mouth. Gill 

 openings rather strongly concave in outline and about evenly spaced, the ist about equal 

 to diameter of eye in small specimens (a little more than i V2 times as long as diameter of 

 eye in diplana of equal size) but about i V2 times in large, the 3rd only a little longer than 

 1st, 5th equal to it or a little shorter, the space between 4th and 5th over origin of pectoral. 

 Nostril sloping a little forward from inner end to outer. Mouth strongly arched, a little 



