Fishes of the Western North Atlantic 137 



Teeth ^^'^^^ in each side of mouth, large/ subtriangular, erect or very slightly 

 oblique, their edges coarsely and regularly serrate; uppers about as high as broad, ist with 

 inner margin nearly straight, but others with both margins usually slightly concave, the 

 outer edge the more so;' lowers narrower than uppers, their margins more concave; ist 

 and 2nd teeth the largest in each jaw, those toward corners of mouth successively smaller, 

 the outermost 2 or 3 minute; ist and 2nd lowers in small specimens (Fig. 22 A, D) with 

 basal serrations considerably the largest; i, or at most 2, series functional in each jaw. Gap 

 at symphysis wider in lower jaw than in upper. 



First dorsal nearly an equilateral triangle, its apex rounded, its rear margin only 

 slightly concave, Its free rear tip only about V4 as long as its base, its origin opposite or a 

 little anterior to inner corner of pectoral.' Second dorsal only y^ to Ve as large in linear 

 dimensions as ist, Its apex rounded, its margins nearly straight, the rear end of Its base 

 over, or a litde anterior to, origin of anal. Upper anterior and lower anterior outlines of 

 caudal moderately convex, posterior outline lunate, with strongly marked subtermlnal 

 notch, the tips subacute, the lower anterior margin about % (76 to 92%) as long as upper 

 anterior margin, each measured from precaudal furrow. Anal similar In size and shape to 

 2nd dorsal, and wholly behind latter. Pelvics much larger than 2nd dorsal or anal, their 

 anterior margins about ^2 as long as anterior margin of ist dorsal, their distal margins 

 concave, their corners rounded. Pectoral noticeably larger in area than in Isurus, a little 

 less than Yi as long as from tip of snout to origin of caudal, and considerably less than V2 

 as broad as long, with convex anterior and concave posterior margins, subacute tip and 

 rounded inner corner. 



Color. Specimens up to 1 2 to 1 5 feet long, including those seen by us, are slaty-brown, 

 dull slate-blue, leaden gray, or even almost black above, shading more or less abruptly 

 to dirty white on the lower surface with a black spot in the axil of the pectoral; the tips of 

 the pectorals also black, usually with some adjacent black spots; the dorsals and caudal 

 dark along rear edges, but the pelvics darkest (olive) along anterior edges, fading rear- 

 ward to white. Large specimens (perhaps some smaller ones also) are described as dun- 

 colored above, or even leaden-white. They may also lack the black axlllar spot." 



Size. This shark has been credited repeatedly with reaching a length of 40 feet. Actu- 

 ally, however, the stated length of the Australian specimen on which the foregoing has 

 been based, the jaws of which are now In the British Museum, was 36V2 feet." The next 

 largest, the actual capture of which is authentically recorded, was reported as of about 30 

 feet, seemingly not measured." However, these appear to have been giants of their kind, 

 for while 20 to 25-footers have been reported as seen on several occasions, the three next 



6. The larg^est teeth of a specimen 36/^ feet long were about two inches long. 



7. Individual teeth vary in this regard, irrespective of their positions along the jaws. 



8. Sometimes shown as a little behind inner corner of pectoral in photographs of specimens suspended by mouth, and 

 hence more or less distorted. 



9. Personal communication from Stewart Springer, from his obser\'ations on about a dozen large Florida specimens. 



10. Giinther, Cat. Fish. Brit. Mus., 8, 1870: 392; Guide to Study Fish., 1880: 321. 

 n. Jordan and Evermann, Bull. U.S. nat. Mus., 47 (i), 1896: 50. 



