Fishes of the Western North Atlantic 239 



Teeth "*°|| , closely crowded, with those of successive rows overlapping; 3 or 4 

 rows functional in front of upper jaw, but only 2 or 3 rows near corners; 3 to 4 rows 

 functional in front of lower jaw, and 5 to 6 rows toward the angles where the serial ar- 

 rangement is increasingly oblique. Upper teeth with 3 cusps, the axial erect or slightly 

 curved and much the longest, with irregular longitudinal striae basally, those toward 

 corners of mouth somewhat smaller, with relatively shorter median cusp and broader 

 base than those in front of mouth; lowers similar to uppers toward center of mouth, except 

 that the outer lateral cusp may be minute or lacking, the teeth along sides of jaw usually 

 with 2 or 3 basal cusps on the inner side, but none on the outer side, so that the cusp that 

 is primarily median is at the outer edge of the tooth. 



Origin of ist dorsal a little behind inner corner of pectoral, its base about as long as 

 from center of eye to ist gill opening, its anterior margin very slightly convex, its apex 

 rounded, its posterior margin slightly concave, the free rear corner a little more than V2 

 as long as its base, the rear end of latter a little anterior to origin of pelvics. Second dorsal 

 similar to ist, and about as high, but about i V2 times as long at base, its origin about over 

 that of anal and slightly closer to origin of caudal than to rear tip of ist dorsal. Caudal 

 Vi to Yz of total length, noticeably narrow, obliquely truncate at tip, with well marked 

 subterminal notch, its rounded, lower anterior corner not expanded to form a distinct lobe. 

 Anal similar to 2nd dorsal in shape, and about as long at base, but only about % as high. 

 Interspace between anal and caudal a little shorter than base of anal, that between anal 

 and tip? of pelvics a little more than V2 as long as base of anal. Pelvics with nearly straight 

 anterior and distal margins but slightly concave inner margins, and broadly rounded outer 

 corners, the inner corners narrowly elongate in both sexes, with pointed tips. Pectoral be- 

 tween 2 and 3 times as large in area as ist dorsal, about % as broad as long, with weakly 

 convex outer and inner margins, very weakly concave distal margin and narrowly rounded 

 corners. 



Color. Upper parts of trunk, caudal, dorsals and pectorals pale gray; lower surface 

 grayish white. At least in some specimens the anterior edge of the dorsals, as well as that 

 of the caudal midway of its length, is marked with faintly defined smoky blotches. The 

 embryo just before birth shows more extensive blotches in these same general regions, 

 in addition to similar blotches on the upper side of the caudal peduncle, on the back mid- 

 way between the two dorsals, and on the side just posterior to the pectoral; also, a sooty 

 area, irregular in outline, extending upward obliquely from the region of the gill open- 

 ings to the dorsal surface of the nape. 



Size, Evidently this is one of the smallest of sharks. The fact that a female of only 

 303 mm. contained two large embryos, and that the claspers in a 338-mm. male are very 

 large and extend rearward as far as the origin of the anal, suggests a maximum length of 

 perhaps not more than about 350 to 400 mm., or about one foot two to four inches. 



Developmental Stages. Two embryos, 90 to 100 mm. long, and nearly ready for 

 birth, contained in a female of 303 mm., resemble the parent, except for the facts that the 



