50 The Alligator and Its Allies 
are near the hinder border of the scales. 
occasionally are two pits 
foundinonescale. These 
pits are found in the gav- 
ials but are absent in 
some, probably all, alli- 
gators. A small knob 
projects from the cen- 
ter of some of the pits. 
These pits are not open- 
ings of glands but have 
about the same structure 
as the pits seen in the 
head. 
The integumental 
bones in the Crocodilia 
originate in the connec- 
tive tissue of the cutis. 
Investigations in young 
animals show that these 
bones usually take their 
origin in the under and 
middle layers of the 
cutis and generally work 
towards the periphery. 
B. THE ENDOSKELETON 
I. The Vertebral Column. 
The vertebral column 
consists of about sixty- 
‘S; 
Bs 
Ke 
D, dorsal region; L, lumbar region; Sa, sacral region; Ri, ribs; Sc, scapula; 
H, humerus: R, radius; U, ulpa; Sta, sternum abdominale: Fe, femur; T, tibia; J, ischium; 
Fic, 16.—Skeleton of Crocodile. 
(From Claus & Sedgwick.) 
C, caudal vertebre. 
