342 



THE AMERICAN MUSEUM JOURNAL 



this fish occurs reguhirly, although not 

 abundantly, in summer along parts of 

 our coast where sea bathing is exten- 

 sively indulged in, it must be regarded 

 as comparatively inoffensive in our 

 waters even if the recent fatalities on the 

 New Jersey coast are attributable to it. 

 The genus Carcharodon reached its 

 climax in the past, during the Eocene 

 or ]Miocene, when fish immensely larger 

 than any now existing must ha\e roamed 

 the seas. It has been thought that, 

 because of the size of the fossil teeth, ^ 

 individuals seventy to eighty feet long 

 must \\Q.\Q been common. The model ^ 

 of the jaws of a shark of this genus in the 

 American Museum of Natural History 

 suggests the colossal proportions at- 

 tained in geological times. In these 

 degenerate modern days the maximum 

 length reached by the white shark ap- 

 pears to be about forty feet, with teeth 

 tliree inches long. The British Museum 

 contains the jaws of a specimen thirty- 

 six feet long from Australia. The gusta- 

 tory feats that can be performed by fish 

 of such size may be judged by the accom- 

 plishment of a thirty-foot indi^•idual on 

 the California coast which had in its 

 stomach an entire sea lion weighing 



who consider the circumstantial evidence suflicieiil 

 to convict the white sheirk in spite of lack of definite 

 proof against it : 



"White sharks are so scarce that their habits are 

 little known, but they are said to feed to some extent 

 on big sea turtles, biting off their legs and even cutting 

 through their shells. Of this species it may be said 

 that judging from its physical make-up it would not 

 hesitate to attack a man in the water. . . .Even a rela- 

 tively small white shark, weighing two or three hundred 

 pounds, might readily snap the largest human bones 

 by a jerk of its body after it had bitten through the 

 flesh. The occurrence of the white shark near New 

 York being almost as unprecedented as the attacks 

 on bathers which happened simultaneou.sly, the cap- 

 lure of a specimen by Mr. Schliesser confirms our 

 belief that the white shark was responsible for the 

 casualties." 



These views of Messrs. Nichols and Murphy are 

 stated in full in the Magazine Seel ion of the New 

 York Times for August 6, 1916. — The Editor. 



1 Opinion of the late Dr. George Brown Goode. 



^ See photograph on back cover of Joun^AL. 



one hundred pounds. The writer has 

 before him a note on a shark of this 

 species collected by a Bureau of Fisher- 

 ies party at Menemsha Bight, Martha's 

 Vineyard, on August 19, 1916; it was 

 twelve feet eight inches long, and more 

 than fi^'e feet in girth at the pectorals, 

 and was estimated to weigh one thousand 

 pounds. 



In the same family with Carcharodon, 

 and distinguished therefrom by haA'ing 

 the edges of the teeth entire instead of 

 serrate, are the mackerel sharks, of 

 which four species may l)e found on the 

 Atlantic coast. ^ One of these, ^ a cos- 

 mopolitan species in temperate lati- 

 tudes, is the "porbeagle" of England, 

 [Isurus uasus (Bonnaterre)].^ It attains 

 a length of ten to twelve feet. The com- 

 mon species on the east coast of the 

 United States is the "blue shark" of 

 the Cape Cod fishermen, [Isurus punda- 

 tus (Storer)l, readily distingviishable by 

 the large black spot on the pectoral fin. 

 It reaches a length of eight to ten feet. 

 The mackerel sharks are handsome, 

 trim, and active species, and are so 

 named Ijecause they are present chiefly 

 during the mackerel season and prey 

 largely on that fish. They are some- 

 times very annoying to purse-seine, 

 pound-net, and gill-net fishermen. 



Related to the mackerel sharks ana- 

 tomically, but dift'ering markedly from 

 them in habits and disposition, is the 

 basking shark or bone shark (Cctorhimis 

 ma.vimus). These names have been 

 applied by our fishermen in allusion to 

 the facts that the fish often remains 



1 All of these are now placed in the genus Isurus by 

 Garman. The Plagioslomia. 191.3. 



2 Another form ranging from New York to the West 

 Indies, was described in 1869 by Captain Atwood as 

 Carchurias ligris but has not been recognized by later 

 writers; it appears to be a distinct species and may be 

 called Isurus tigris. It attains a length of ten feet or 

 more. 



' Generally recorded in recent literature under the 

 navae Lamna cornubica (Gmelin). 



