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/E 
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 
