274f Bulletin 4.7, United States National Museum. 



dnced acute posterior lobe; vertical height of fin exceeding length of base, 

 the anterior lobe very high, extending beyond tip of posterior when the 

 fin is declined, equaling $ length of anterior margin of pectoral; pos- 

 terior margin of dorsal 3 in the anterior margin; base of first dorsal 

 contained 2 times in interspace between dorsals ; base of second dorsal 6? 

 times; margin of second dorsal gently concave; front margin low, the 

 angle broadly rounded, barely reaching posterior end of base when fin is 

 declined ; posterior lobe much produced and acute, slightly longer than 

 l>ase of fin, the latter If in the distance from its base to front of caudal 

 pit; upper lobe of caudal 3f in total length, the lower lobe 2\ in the 

 upper; terminal lobe of caudal 3| in the upper lobe; anal larger than 

 second dorsal, higher, with deeply incurved margin, its base a little 

 longer, its origin slightly in advance of that of second dorsal, the pos- 

 terior insertions of the two fins nearly opposite; length of anal base If 

 in its distance from anterior edge of caudal pit. Color bluish above, 

 whitish or grayish below ; free margin of pectoral narrowly white, the 

 anterior edge narrowly bordered with black, most evident when seen 

 from the outer surface, the inner surface being dusky; first dorsal un- 

 marked, the second dorsal with dusky anterior lobe; upper edge of caudal 

 black, the lower margin faintly dusky; fins otherwise unmarked. A 

 single specimen, a female 4 feet long, was procured from the Panama 

 market. As preserved, it is partially skinned. The following measure- 

 ments were taken when the specimen was intact, before preservation. 

 Where not agreeing with dimensions given above, the latter will be found 



more reliable : 



Inches. 



Tip of snout to insertion of dorsal 16J 



Base of first dorsal 4$ 



Distance between dorsals 11 



Base of second dorsal If 



From second dorsal to front of caudal pit 2$ 



Front of caudal pit to tip of caudal 13J 



Tip of snout to axil of pectoral 15 



Axil of pectoral to front of base of ventrals 11J 



Front of ventrals to front of anal 6 



Front of anal to front of caudal pit 4 T 9 B 



Girth at front of first dorsal 17f 



Distinguished from other known sharks of the Pacific coast of America 

 by the excessively long, slender, acute snout, the slender body, and the 

 very long caudal fin. Panama; only the type known, (velox, swift.) 



Carcharhinus velox, GILBERT, Fishes of Panama, MS. 1898, Panama. (Type, No. 11893, 

 L. S. Jr. Univ. Mus. Coll. Dr. Gilbert.) 



Page 42. Scoliodon longurio has the teeth serrulate at base only. The 

 base of the first dorsal is 2f in the interspace between the dorsals. 



Page 44. Sphyrna Hburo occur also in the Pacific. We have recently 

 secured specimens at Mazatlan, where S. tudes and S. zyga>na are also 

 found. 



Page 47. Carcharias Utloralis reaches a length of 8 feet 7 inches. (Spec- 

 imens from Beaufort, North Carolina. Coll. H. H. Briinley.) 



