54. GOPHERUS 993 



around the edges of the shell. During copulation the male 

 stamps his hind feet and utters a mechanical grunt with the 

 head hooked over the end of the plastron and the mouth half 

 open. 



"Stephens (1914, p. 135) writes that teeth marks are 

 sometimes seen on shells of living tortoises and believes that 

 the shells "generally prove too hard for the coyotes." The 

 younger tortoises are soft-shelled and delicate. They prob- 

 ably fall prey in numbers to raptorial mammals and birds. 

 The old ones are a favorite delicacy among the Indian and 

 Mexican section-hands who live with their families along 

 the railroad lines. Some tortoises kept as curiosities at 

 Needles on a grass plot in front of the Santa Fe hotel are 

 thought to have been gradually depleted by the inroads of 

 the Indians, many of whom lounge about the place." 



Family 19. CHELONIID^ 



This family is composed of all the marine turtles except 

 the so-called leather-back turtles. They are turtles with 

 paddle-shaped limbs, bony carapaces covered with horny 

 plates, and head and limbs covered with scales. They in- 

 habit the tropical and semitropical oceans. There are no 

 authentic records of any of these turtles having been taken 

 on the western coast of the United States, but they occur 

 about the shores of southern Lower California. Individuals 

 are said to reach a length of seven feet and a weight of 

 eight or nine hundred pounds. The three kinds are known 

 as green turtles, loggerhead turtles, and hawk-billed or tor- 

 toise-shell turtles. The first is the soup turtles of commerce. 

 The last furnishes the tortoise "shell" of which combs and 

 similar articles are made. The loggerheads are the most 

 pelagic, and ordinarily are not used as food, or otherwise. 

 All of the species resort to sandy shores to lay their eggs in 

 holes which they dig a short distance above tide line. The 



