FAMILY SQUALID^. 357 



GENUS SELACHUS. Cuvier. 



Branchial apertures all before the pectorals, long, and nearly surrounding the neck. Teeth 

 small, not denticulated, of various forms, for the most part conical. 



Obs. This genus comprises at present but one well determined species, which has been 

 reproduced under different names. 



THE BASKING SHARK. 



Selacmus maximus. 



TLATE LXIII. FIG 208. (Male.) 



Squalus maximus. Linneus. 



S. pcregrinus. Blainville, Ann. Mus. Vol. 18, pi. 6, fig. 1. 



Squalus maximus, Basking Shark. Mitchill, Trans. Lit. and Phil. Soc. Vol. 1, p. 486. 



S. clephas. Lesiteur, Jour. Acarl. Nat. Sciences, Vol. 2, p. 343, pi. 11. 



S. maximus. Richardson, Faun. Bor. Americana, Vol. 3, p. 291. 



5. (Sclache) maximus. Storer, Massachusetts Report, p. 407. 



Characteristics. Dark slate. Tail with a carina on each side. Length exceeding thirty feet. 



Description. Body cylindrical, fusiform. Surface with numerous wrinkles, and covered 

 with minute sharp prickles, distributed in small groups, and producing a roughness in the 

 direction of the head. Head small. Snout smooth, blunt, and furnished with numerous cir- 

 cular and oblong mucous pores. Temporal orifice very small, and placed just over and behind 

 the angle of the jaws. Eyes very small, not exceeding three inches in diameter, and placed 

 on the margin of the upper jaw. Branchial apertures with the posterior pair smallest, the 

 anterior nearly meeting beneath. The nostrils anterior to the eyes, on the edge of the upper 

 lip. Teeth in the upper jaw, of various forms, recurved, edged but not serrated, subconic, 

 triangular-conic and even bifid, in six.rows ; in the lower jaw, with seven rows, rather larger, 

 sublanceolate, conic, elongate ; (according to Dr. Storer, fourteen hundred in the lower jaw 

 alone.) 



The first dorsal fin triangular, concave behind, about four feet high, pointed behind. The 

 second arises six feet behind the first ; small, sixteen inches high ; its origin anterior to the 

 anal, and pointed behind. Pectorals large, falciform, and five feet and a half long, with a 

 base of nearly two feet. Ventrals subtriangular, and nearly equidistant between the first and 

 second dorsal, with a base of nearly two feet. Male organs about three feet long, and cylin- 

 drical. Anal fin three feet behind the vent, subtriangular, with a pointed process behind. 

 Tail with a strangulated appearance above, and below at the base of the caudal, and an ele- 

 vated keel on its sides nearly two feet long. The caudal fin with unequal lobes ; the upper- 

 most six feet long, with a small triangular fin near the tip ; the lower lobe shorter, four feet 

 long, and wide. 



