332 Memoir Sears Foundation for Marine Research 



moderately convex, its terminal sector only about Vs of total length of fin, slender, with 

 rounded tip and weakly concave lower margin, its lower lobe (expanded anterior corner) 

 about % (42%) as long as upper lobe with convex lower anterior margin and narrowly 

 rounded tip ; general posterior re-entrant contour, included by the two lobes, more broadly 

 rounded than in C. fioridanus (cf. Fig. 56 with 58). Anal about as long at base as 2nd dor- 

 sal, or a little longer, with similarly slender free rear tip, about i V2 times as long as the 

 vertical height and about as long as the base, but with much more deeply incised rear mar- 

 gins and more broadly rounded apex. Distance from origin of anal to tips of pelvics about 

 2V2 times as long as base of anal. Pelvics a little longer at base than anal, with nearly 

 straight edges, their origins about midway between origins of ist and 2nd dorsals. Pectoral 

 only about % as long as head (about as long as head in fioridanus) and only about twice 

 as long as vertical height of ist dorsal, a little more than twice as long as broad, the outer 

 margin weakly convex toward tip, distal margin moderately concave, inner margin only 

 weakly convex, inner corner and apex narrowly rounded. 



Color. Described as dark gray above, grayish white below j those we have seen after 

 preservation are mouse gray above and a paler shade of the same tint below. 



Size. The claspers of the males listed above have not yet reached the tips of the pelvic 

 fins, and a female of 7% feet has been found to contain embryos.^^ These facts suggest that 

 falciformis matures at a length of perhaps six feet, but it is said to attain a length of about 

 10 feet (3,050 mm.).'^ 



Developmental Stages. It is not yet known whether this is an ovoviviparous or a vi- 

 viparous species; its embryos have been reported only once." 



Habits. While several falciformis have been taken on set lines along the reef off 

 Metacumbe Key in southeastern Florida during summer in about 60 feet of water, none 

 have ever been reported in the passages between the Keys, in spite of the great amount of 

 angling that is done from the bridges that span the latter; similarly, one of the three 

 records of it farther to the north was from the outer edge of the continental shelf, the 

 other two being from about 1 7 to 20 miles out from the nearest land, although taken in 

 shoal water of 14 to 15 fathoms. Thus it appears that this is an oflFshore species, not to be 

 expected close to the beach unless as a stray. Nothing further is known of its habits, and 

 nothing of its diet." 



Relation to Man. Falciformis is not caught anywhere in numbers large enough to 

 make it of commercial importance. 



Range. Both sides of the Atlantic, in waters of high temperature; Goree, West Africa, 

 on the one side, West Indies to the offing of Delaware Bay on the other. So far known in 

 the western Atlantic from: Trinidad (nominal record only); Porto Rico; Haiti; Ber- 

 muda; Cuba; Bahamas; east coast of Florida (Salerno), where half -grown specimens as 



11. Personal communication from Stewart Springer. 



12. 3,050 mm. (Fowler, Bull. Amer. Mus. nat. Hist., 70 (i), 1936; 49). 



13. Personal communication from Stewart Springer. 



14. The head of a menhaden (Brevoortia), found in the stomach of one of the present series taken off Cape Fear, 

 North Carolina, may have been a bait taken from a hook before this Shark was caught. 



