138 Philippine Journal of Science 1920 
Measurements of Chelonia japonica (Thunberg) . 
mm. 
Total length 
735 
Length of carapace 
555 
Width of carapace 
470 
Height of carapace 
180 
Length of plastron 
448 
Width of plastron, across pectoral 
290 
Length of head 
125 
Width of head 
90 
Depth of head 
100 
Tail, behind anus 
28 
Variations . — The head shields of this species are subject to 
more or less variation. In a second specimen living in the 
aquarium there is a second pair of prefrontals bordering the 
nasal area but not touching the beak. These shields are small 
and irregular. 
Remarks . — The species is common in the Philippine Islands. 
Specimens have been kept alive in the aquarium. They are very 
frequently taken in Manila Bay, They are fed on fish. 
Suborder CHILOT^ 
Chilotae Wiegmann, Hartdb. Zool. (1832) 167. 
This suborder consists of one family. 
TRIONYCHID^ 
Trionychidm Bell, Zool. Journ. 3 (1828) 515. 
Carapace and plastron without outer scales or shields and not 
entirely ossified, covered with leathery skin; head completely 
retractile; no external ear; bony part of jaws concealed under 
thick lips; three digits with claws; nostrils at end of a flexible 
proboscis. 
Only a single genus of this family is positively known from 
the Philippine Islands. Species of three other genera have been 
reported but probably erroneously. They are the following: 
Dogania subplana (Geoffrey Saint Hilaire.) Reported by Casto de 
Elera as T [rionyxl subplanus, from Mindanao and Palawan, 
with specimens in the Santo Tomas Museum and in turn listed 
from the Philippines by Siebenrock“ and de Rooij,” on the strength 
of Casto de Elera’s record. No specimen is now in the Santo 
Tomas Museum. 
Chitra indica Gray. This species was first reported from the Phil- 
ippine Islands by Gray, who later made the specimen the type 
“’Cat. Fauna Filipinas 1 (1895) 407. 
“Zool. Jahrb. Suppl. 10 (1909) 606. 
“ Rept. Indo-Aust. Arch. 1 (1915) 326. 
