380 Memoir Sears Foundation for Marine Research 



Trunk moderately stout, as in leucas, its height at ist dorsal about Vr> its length to 

 origin of caudal. Back without trace of median dermal ridge. Upper precaudal pit strongly 

 marked, semi-lunar, the lower smaller but still apparent. Dermal denticles overlapping 

 in varying degrees, with skin more or less exposed between their blades, thick, strongly 

 arched and rising steeply, about as broad as long, usually with 3-5 high, sharp-topped 

 ridges, 3, 4, or 5 blunt teeth, the median much the longest 5 pedicels verv broad and stout 

 as in leucas. 



Head strongly flattened above and very wide anteriorly, its breadth about % as great 

 at eyes as at origin of pectoral. Snout very broadly rounded and shorter than in any other 

 local Carcharhinus, its length in front of a line connecting outer ends of nostrils only a 

 little more than Vz as great as distance between inner ends of latter, the length in front of 

 mouth about V4 to V3 (27 to 33%) that of head to origin of pectoral. Eye noticeably 

 small as in leucas, its diameter about '^/o as great as distance between nostrils. Nostril 

 strongly oblique, its inner end only a little more than V2 as far from mouth as from tip of 

 snout, its anterior margin expanded toward inner end in subrectangular outline, much as in 

 leucas. Gill openings about evenly spaced, the ist to 3rd between V2 and % as long as dis- 

 tance between nostrils or about 3V2 times as long as diameter of eye, the 5th about % as 

 long as 1st, the 3rd over origin of pectoral. Mouth broadly rounded, its height about V2 

 its breadth. Upper labial fold so short as to be easily overlooked. 



Teeth '^ "'' '^^Y— 12'^ ""^ '^ > shaped much as in leucas; uppers broadly triangular, their 

 edges moderately serrate from tip to base, the ist and 2nd teeth symmetrical, erect, their 

 edges slightly concave, but successive teeth increasingly oblique along the jaw with outer 

 edges increasingly concave in rounded or subangular contour, the 9th to 13th with inner 

 edge convex, and successively smaller, the outermost very small ; lower teeth erect, sym- 

 metrical, with narrow triangular cusps on broadly expanded bases, the cusps finely serrate 

 and bases partially so, the 9th to 12th successively smaller, with relatively lower cuspj a 

 very small symmetrical tooth at symphysis on lower jaw, i present or not in upper."* 



First dorsal of about same size relatively as in leucas, with a similar subacute apex, 

 but somewhat more erect in specimens seen, and with a relatively somewhat longer free 

 rear corner (about Vs as long as the base), its origin a little anterior to axil of pectoral. 

 Second dorsal about Yi as long at base as ist, as in leucas, and of the same general form 

 except that the free rear corner is about 73 as long as base (only about V2 that long in 

 leucas), and the rear margin somewhat more deeply concave, its origin slightly but defi- 

 nitely anterior to origin of anal. Caudal about 28% of total length, of same shape as in 

 leucas. Distance from lower origin of caudal to tip of anal about V2 as long as base of latter. 

 Anal about as long at base as 2nd dorsal, and nearly i V2 times as long on anterior margin, 

 its shape as in leucas. Distance from origin of anal to tips of pelvics about V2 as long as base 

 of former. Pelvics a little longer along anterior margins than 2nd dorsal and a little shorter 



106. This tooth is recorded for the type specimen (Gill and Bransford, Proc. Acad. nat. Sci. Philad., 1877: 190) but 

 is lacking in one which we have studied. 



