Fishes of the Western North Atlantic 151 



margin (lower lobe) about 60-65% ^s long as upper, each measured from the precaudal 

 pit, its tips subacute. Anal similar to 2nd dorsal, and about as large, its origin under rear 

 part of base of latter. Pelvics about % as high as ist dorsal along anterior margin. Claspers 

 described as about 3 feet 3 inches long in 30-foot male. Pectoral with straight or slightly 

 concave distal margin and blunt tip, but broadly rounded inner corners, relatively smaller 

 than in Isurus, the length along anterior margin being only about Vs of distance from 

 snout to origin of caudal. 



Color. Grayish-brown to slaty gray, or nearly black above. The under parts may be 

 either uniformly of the same color as the back, of a paler shade of the same, or grading 

 into white, sometimes with a triangular white patch under the snout and with two pale 

 bands along the ventral surface on either side of the midline or otherwise marked with 

 white, there being a wide variation in this respect. 



Size. The Basking Shark rivals, although it does not equal, the Whale Shark (p. 

 192) in size. It has been credited repeatedly with reaching a maximum length of 40 to 

 50 feet. For Basking Sharks to reach lengths of 35 to 40 feet is not exceptional, for one 

 of about 45 feet and three of about 40 feet, as well as smaller ones, were taken on the 

 Norwegian coast during the period 1884 to 1905.^^ The six next longest actually meas- 

 ured were 36 feetj 32 feet 2 inches; 32 feet; 31 feet; 30 feet 6 inches; and 30 feet 3 

 inches. The four largest, for which we find exact measurements for the western Atlantic, 

 were 32 feet 2 inches, 32 feet, 30 feet 3 inches, and 26 feet 6 inches, although others up to 

 40 feet have been reported without supporting evidence. Similarly, the longest of 21 

 Basking Sharks landed in Monterey, California, from November to February of 193 1, was 

 about 28 feet; the largest ever sold to the particular fishery firm in question was a few 

 inches less than 30 feet." 



The smallest free-living specimens of which we find record were of 5 feet 5 inches," 

 8 feet 4 inches,'" and about 8 feet 6 inches (2.6 m.)," which suggests that Basking Sharks 

 are as a rule at least 5 to 6 feet long at birth. Males mature at a length of perhaps 1 5 to 20 

 feet as indicated by the presence of small claspers in specimens up to about 1 1 feet, with 

 very large ones in specimens of 25 to 26 feet or longer.'* Similarly, most described speci- 

 mens of less than 1 1 to 13 feet have had the immature, proboscis-like form of snout. On 

 the other hand, a 14-foot 3-inch specimen taken recently near New York showed an inter- 

 mediate state,'^ and all specimens of 20 feet or upward, for which adequate information 

 is at hand, have been of adult conformation in this respect. 



We have not succeeded in finding precise weights for the larger sizes in the Atlantic. 

 But since the two Monterey specimens just quoted actually weighed 6,580 pounds at 28 

 feet and 8,600 pounds at about 30 feet, this no doubt is a fair indication of the weight of 



13. Collett, Norges Fiske, j, 1905: 83-86. 14. McGinitie, Science, N.S. 75, 1931 : 496. 



15. Thompson, Nat. Hist. Ireland, 4, 1856: 253. 16. Pengelly, Zoologist, (3) 5, 1881: 337. 



17. Nobre, Fauna Marinha Port. Vert., /, 1935: 441. 



18. Pavesi, Ann. Mus. Stor. nat. Genoa, 12, 1878: 398, 406. 



19. Gudger, J. Morph., 57, 1935 : 96. 



