392 Memoir Sears Foundation for Marine Research 



1st and 2nd dorsal fins. Upper precaudal pit well marked, subangular, a little less than a 

 right angle, the lower pit only faintly indicated. Dermal denticles overlapping only 

 partly, with the skin visible between them here and there, their blades broader than long, 

 usually with 3 (rarely 5) strong longitudinal ridges and as many moderately strong 

 teeth, the median a little the longest j pedicels very short. 



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Figure 73. Carcharhhms oxyrhynchus. A, B Immature male, about i8 inches long, from Surinam, somewhat 

 emended after Muller and Henle. C Upper and lower teeth, after Muller and Henle. D An upper and a 

 lower tooth, much enlarged, after Muller and Henle. E Dermal denticles from a female, about 443 mm. 

 long, from Surinam, much enlarged (see Study Material, p. 391). 



Head with snout relatively much longer than in other local species of CarcharhinuSy 

 its length to origin of pectoral about 40% of length of trunk to origin of caudal in the 

 original illustration. Snout narrow, wedge-shaped, contracted anterior to nostrils, with 

 narrowly rounded tip, its length in front of a line connecting outer ends of nostrils 

 about I V2 times as great as distance between inner ends of latter, its length in front of 

 mouth about twice as great as distance between nostrils or about Y^ ^s great as length of 

 head to origin of pectoral."" Anterior margin of eye very little posterior to front of 

 mouth. Gill openings about twice as long as diameter of eye, the space between 4th and 

 5th over origin of pectoral.^^' Nostril only slightly oblique, its inner end only about V2 

 as far from front of mouth as from tip of snout, its anterior margin only slightly expanded, 



130. This is according to the original illustration; in the dried skin the head has obviously been lengthened in the 

 process of stuffing. 



131. In the stuffed skin the 5th is a little anterior to the origin of the pectoral, but this is probably due to distortion. 



