206 REPORT OF NEW JERSEY STATE MUSEUM. 
Family CHELONIID. 
The Logger Head Turtles. 
Carapace depressed, heart-shaped, broad, flat, highest in front, 
widest near middle, and covered with bony plates. Head large, 
subquadrilateral, and covered with plates. Neck bending by 
sigmoid curve in vertical plane, short, thick, and incompletely 
retractile. Jaws without tooth-like projections. Parietals pro- 
longed downwards forming a suture with pterygoids, or separated 
from latter by interposition of epipterygoid, and in contact with 
squamosal, and latter also forming suture with parietal. Ptery- 
goids in contact in median line, narrpw in middle. Nuchal plate 
without costiform processes. Mandible with articulary concay- 
ities. Outer border of tympanic cavity deeply notched. Mandi- 
ble with articulatory concavities. Temple completely roofed over. 
Dorsal vertebree and ribs immovably united and expanded into 
bony plates forming carapace. A complete series of marginal 
bones connected with ribs. Cervical vertebrz without or with 
mere indications of transverse processes, short, and mostly artic- 
ulated by amphiarthrosis. Centrum of last cervical articulating 
with that of first dorsal. Caudal vertebrz proccelous. Plastral 
bones 9. Epiplastra in contact with hypoplastra. Entoplastron 
if present oval, rhomboidal or ‘T-shaped. Pelvis not anchylosed 
to carapace and plastron. Limbs paddle-shaped. Phalanges 
without condyles. Claws I or 2. 
Among the largest marine turtles in the open seas, visiting 
the shore only to deposit and bury their eggs. ‘Two genera are 
represented along our coast. 
Key to the genera. 
a. Head broad; edge of lower jaw not serrate; scales around large median 
plate on top of head 13 to 20; costal plate 5 on each side. CARETTA 
aa. Head high and narrow; tomia of lower jaw serrate; scales around vertical 
plate 7; costal plates 4. CHELONIA 
