440 Memoir Sears Foundation for Marine Research 



more than ' j as high as broad, with a very short labial furrow on lower jaw from corner 

 of mouth, but none on upper jaw. 



Teeth "i2°t'o^H— °i— il'o 'V^ '"■ specimens counted, uppers triangular, the cusps smooth- 

 edged in young, but tending to become weakly serrate with growth,^^" the bases more or 

 less fluted or wavy on outer side of some teeth but not on others j the ist upper tooth nearly 

 symmetrical and erect, but subsequent upper teeth strongly oblique, their inner margins 

 straight or slightly convex, their outer margins deeply incised, even the outermost with 

 cusps well developed though very small j lower teeth similar to uppers but a little smaller, 

 smooth or very weakly serrate, the 4 next to the center of mouth with narrower cusps and 

 less strongly oblique; i small symmetrical tooth at symphysis of lower jaw, one or none in 

 upper in specimens examined; i (in places 2) series functional along sides of mouth and 2 

 to 3 series toward center in upper jaw; 2 to 3 series all along lower jaw. 



First dorsal perhaps averaging a little more sloping than in diflana, a perpendicular 

 from its apex falling a little anterior to its tip, its origin a little posterior to axil of pectoral, 

 its vertical height a little more than Y2 (50 to 58%) as great as length of head, its 

 anterior margin only slightly convex toward apex, posterior margin moderately concave 

 toward base, apex very narrowly rounded, its free rear corner only moderately slender, 

 a little less to a little more than ^/"s as long as the base, the midpoint of its base about 

 2.5 times as far from origin of pelvics as from axil of pectoral. Second dorsal about Va ^s 

 long at base as ist, its origin about over midpoint of base of anal, its apex abruptly rounded, 

 rear margin moderately concave, its free rear corner very slender, a little longer than the 

 base. Caudal nearly Yi of total length, its upper margin varying from very weakly con- 

 vex to a little more strongly so toward base and tip; the terminal sector a little more than 

 Viy the length of fin, slender, with narrowly rounded tip, its lower posterior margin only 

 weakly concave (less deeply so in specimens seen than in diflana), the lower lobe a little 

 more than y^ as long as upper with weakly convex anterior margin, nearly straight pos- 

 terior margin, and narrowly rounded tip, the re-entrant contour, enclosed by the 2 lobes, 

 approximately a right angle, with rather broadly rounded corner. Anal about i Vs to i V2 

 times ( 1 .3 to 1.6) as long at base as 2nd dorsal and a little higher, its anterior margin more 

 convex, apex acute, rear margin m.uch more deeply incised in angular contour, its free rear 

 corner about as long as the base or a little longer. Distance from origin of anal to tips of 

 pelvics I '/'s to I V2 times as long as base of former. Pelvics about as long at base as anal. 

 Pectoral a little less than % (59 to 64%) as long as head, about as long as vertical height 

 of ist dorsal or a little longer, a little smaller than ist dorsal in area, a little more than V2 

 as broad as long, the outer margin nearly straight, distal margin only slightly concave, the 

 apex and inner corner narrowly rounded. 



35a. Stewart Springer informs us that in large zygaena the upper teeth may have noticeable serrations while the 

 lowers may have extremely fine serrations or none. In a specimen about six feet long (1,780 mm.), caught in 

 August 191.6 off Woods Hole, Massachusetts (Harv. Mus. Comp. Zool., No. 36425), the teeth, both uppers 

 and lowers, vary from smooth to very weakly serrate or slightly irregular. 



