50 
NORTH AMERICAN BA TRAC III A AND REPTILIA. 
1). Shield completely ossified. 
x. Fingers and toes not bound closely together; more 
than the distal phalanges free. 
“Tail crested, very long and strong; plastron 
narrow and small; bony vertebral plates 12, 
continuous the whole length of carapace; 
plates of plastron nine; head large; neck long 
and stout ; body highest in front . . Ckelydridce. 
**Tail short ; plastron usually broad and large. 
1. Lower jaw with a long, strong, sharp point 
at symphysis ; bony vertebral plates from 5-7, 
not continuous; plates of plastron eight in 
adult ; iliac bones arched outwards ; coracoids 
reaching back of middle transverse suture of 
plastron; coracoid and pubis closely approxi- 
mated; skin loose on knees and elbows; tail 
tipped with a horny spur in males. 
Cinosternidce. 
2. Lower jaw without long point at symphysis ; 
bony vertebral plates 10, continuous; plates of 
plastron nine ; iliac bones nearly parallel ; cor- 
acoid not reaching middle transverse suture; 
skin clinging more or less to knees and elbows. 
EmydidcB. 
y. Fingers and toes bound closely together; only the 
last joint free; bony vertebral plates about 10; 
plates of plastron nine ; iliac bones wider apart at 
hip joints than at sacrum Testudinidce. 
Family SPIIARGIDIDJL 
Body highest in front and widest at the anterior edge of the 
bridge; posterior limbs much exposed; head high, short and very 
broad at the back; two pits and two teethdike projections on the 
upper jaw; a single, median projection on the lower. There is 
but one genus in the family. 
Genus Sphargis, Merrem. 
Body covered by a smooth coriaceous skin; feet without 
nails; several longitudinal ridges along carapace. 
91. S. coriacea , Rondelet. Leathery Turtle. Color above 
dark brown; below whitish; nodules along the longitudinal 
ridges of carapace. On the Atlantic coast to Massachusetts. 
