220 



BACKBONED ANIMALS. 



The eye-openings are placed vertically. They attain a 

 length of eight feet, and a weight of twelve hundred 

 pounds.* The loggerhead f is nearly as large. Its shell 



is made up of 

 scales. They 

 breed upon 

 Loggerhead 

 Key, Florida, 

 and other lo- 

 calities, bury- 

 ing their eggs 

 in the sand, 

 leaving the sun 

 to hatch them. 



FIG. 265. Green turtle. The digging 



and covering is 



done by the hind-flippers. The green turtle (Fig. 265) 

 is somewhat similar, though more delicate, the head, and 

 flippers smaller. They feed upon algae, particularly Zos- 

 tera marina. The hawkbill \ (Fig. 266) is distinguished 



* The gigantic extinct Protostega gigas was allied to the Sphargis. 

 It measured seventeen feet between the fore-arms or flippers, and 

 was remarkable for the rudimentary character of the bones in the 

 adult. 



f The loggerhead is extremely powerful, and I have found it diffi- 

 cult to turn one with the help of two men. By seizing them by the 

 shell just over the head I have been carried a long distance in the 

 water at a rapid rate. The steeds thus experimented upon were kept 

 in an inclosure half a mile long and eight feet deep, and when asleep 

 on the bottom could generally be caught by diving. Owing to their 

 sluggish natures they often fall a prey to sharks to the extent of their 

 flippers. I have caught them in the Gulf Stream with these organs 

 entirely bitten off. 



\ Though the hawkbill is a vegetable feeder as a rule, they some- 

 times attack the Physalia (Fig. 19). One, two feet long, was found by 

 the author floating on the surface, insensible, its head covered by the 

 blue tentacles. By scraping them off with a knife the turtle recovered, 

 and was kept as a pet for a long time. 



