118 
Philippine Journal of Science 
1920 
CLASSIFICATION OF THE TURTLES 
Stejneger’s ® system of classification is followed in this paper. 
Class REPTILIA 
Reptilia Laurenti, Synops. Kept. (1768) 19. 
Subclass SYNAPSIDA 
Synapsida OsBORN, Science 17 (1903) 276. 
Order TESTUDINATA 
Testudinata Oppel, Ordn. Kept. (1811) 3. 
Key to the Philippine suborders of Testudinata.” 
No solid carapace, the vertebrEe and ribs being separated from a shell 
consisting of a mosaic of numerous small polygonal bony plates 
embedded in a leathery skin; no descending process of the parietal 
bone; limbs without claws Athecse. 
A solid carapace, of a few large symmetrical bony plates, not separated 
from the underlying vertebrae and ribs; parietals with descending 
processes; limbs with at least one claw each. 
K. Body covered with horny scutes arranged differently from the bony 
plates beneath; epiplastra and hyoplastra in contact, not separated 
by entoplastron ; center of last cervical and first dorsal vertebrae 
articulating Vvith each other; fourth digit never with more than 
three phalanges; jaws covered by horny sheaths not concealed 
under fleshy lips Laminifera. 
Body covered by an undivided leathery skin without scutes ; epiplastra 
separated by entoplastron from hyoplastra; last cervical vertebra 
articulating with first dorsal by zygapophyses only; fourth digit 
with more than three phalanges; jaws concealed under fleshj’- lips. 
Chilotas. 
Key to the Philippine families of turtles^ 
a\ Limbs clawless; skin with very numerous polygonal plates; back with 
five longitudinal keels or ridges (Athecse) Dermochelidae. 
a*. Limbs with at least one claw each; skin with or without large regular 
plates; back, if keeled, with at most only three longitudinal keels. 
P. Outer body covering a soft skin without horny plates (Chilotse). 
Trionychidae. 
K. Outer body covering consisting of symmetrical horny plates (Lam- 
inifera) . 
"Bull. U. S. Nat. Mus. 58 (1907) 483 and 484. 
“ A species belonging to the Platysternidae has been incorrectly reported 
from the Philippines by Casto de Elera and by Siebenrock. 
