538 The True Sharks 



Isiints oxyrhynchus occurs in the Mediterranean, Isnropsis dekayi, 



in the Gulf of Mexico, and Isuropsis glauca, from Hawaii and 



japan westward to the Red Sea. 



Man-eating Sharks. — Equally swift and vastly stronger than 



these mackerel-sharks is the man-eater, or great white shark, 

 Carcharodon carcharias. This shark, foimd 

 occasionally in all warm seas, reaches a length 

 of over thirty feet and has been known to 

 devour men. According to Linnaeus, it is the 

 animal which swallowed the prophet Jonah. 

 " Jonam Prophetum," he observes, "ut veteris 

 Herculem trinoctem, in hujus ventriculo tri- 



^"/.;«r«.!~'^fc°!lafc dui spateo bcEsisse, verosimile est." 

 (Agassiz). Mio- j^ ^g beyond comparison the most vo- 



cene. Family Zynm- ._,,., . , ^^ o 



ludce. (After Nich- racious of tish-hke animals. Near boquel, 

 "'^""■^ California, the writer obtained a speci- 



men in 1880, with a young sea-lion (Zalophus) in its stomach. 

 It has been taken on the coasts of Europe, New England, Caro- 

 lina, California, Hawaii, and Japan, its distribution evidently 

 girdling the globe. The genus Carcliarodon is known at once b}' 

 its broad, evenly triangular, knife-like teeth, with finely serrated 

 edges, and without notch or cusp of any kind. But one species 

 is now living. Fossil teeth are found from the Eocene. One of 

 these, Carcliarodon juce^alodoii (Fig. 332), from fish-guano deposits 

 in South Carolina and elsewhere, has teeth nearly six inches long. 

 The animal could not haA'e been less than ninety feet in length. 

 These huge sharks can be but recently extinct, as their teeth 

 have been dredged from the sea-bottom by the Cliallenger 

 in the mid-Pacific. 



Fossil teeth of Lamna and Isiirus as well as of Carcharodon 

 are found in great abundance in Cretaceous and Tertiary rocks. 

 Among the earlier species are forms which connect these genera 

 verv closely. 



The fossil genus Otodns must belong to the Lamnidcc. Its 

 massive teeth with entire edges and blunt cusps at base are 

 common in Cretaceous and Tertiary deposits. The teeth are 

 formed much as in Lanina, but are blunter, heavier, and much 

 less effective as instruments of destruction. The extinct genus 

 Corax is also placed here by Woodward. 



