3i6 Memoir Sears Foundation for Marine Research 



Key to Species 



I a. Snout in front of mouth considerably longer than breadth of mouth. 



2a. Tip of 1st dorsal terminates anterior to origin of pelvics by a distance at least as 



long as base of latter j origin of 2nd dorsal opposite or only a very little posterior 



to origin of anal. signatus Poey, 1868, p. 316. 



2b. Tip of 1st dorsal reaches nearly to a perpendicular at origin of pelvics; origin of 



2nd dorsal over or posterior to midbase of anal. 



macloti Muller and Henle,' 1841. 

 New South Wales, East Indies, India; also 

 probably Chile.* 



lb. Snout in front of mouth not longer than breadth of mouth. 



3a. Base of 2nd dorsal only % as long as base of anal; posterior margin of 2nd dorsal 

 not concave, but that of anal deeply so j upper teeth oblique, lowers erect. 



hemiodon Muller and Henle, 1 841. 



Arabian Gulf, India, Indo-China, East In- 

 dies, Philippines.' 



3b. Base of 2nd dorsal as long as base of analj 2nd dorsal of same shape as anal; 

 upper teeth erect, like lowers. ■playfairii Gunther, 1 870. 



Madagascar. 



Hypofrion signatus Poey, 1868 



Night Shark 



Figure 54 



Study Material. Immature female, 935 mm. long, from offing of South Carolina, 

 Lat. 33° 37' 30" N., Long. 77° 36'3o" W., in 14 fathoms on October 20, 1885 (U.S.Nat. 

 Mus., No. 38508) ; three embryos (two females, one male), 385 to 407 mm. long (Harv. 

 Mus. Comp. ZooL, No. 36091); also photograph of adult female taken oflf north coast 

 of Cuba.* 



Distinctive Characters. Easily separable from all other local carcharhinids by the 

 combination of very long, pointed snout with smooth-cusped teeth, but the uppers strongly 

 serrate at the base, and with the presence of a low but unmistakable mid-dorsal ridge. 



Description. Proportional dimensions in per cent of total length. Female, 935 mm., 

 from Lat. 33° 37' 30" N., Long. 77° 36' 30" W. (U.S. Nat. Mus., No. 38508). 



3. Proportional dimensions calculated from measurements given by Muller and Henle (Plagiost., 1841 : 34) for the 

 type specimen. 



4. Reported as Hyfofrion ? {Hemigaleus i ) /leterodus and Hyfoprion J (Hemigaleus ? ) isodus by Philippi (An. 

 Univ. Chile, yt, 1887: 541, 542). 



5. According to Whitley (Fish. Aust., i, 1940: 107), a report of this species from South Australia by Zietz probably 

 was not correct. 



6. Contributed by Luis Howell-Rivero. 



