502 S. R. DETWILER 
While the central part of the girdle is chondrified before the first 
two digits of the fore limb are fully formed and before the elbow 
joint becomes visible, the dorsal portion of the suprascapula is 
not entirely chondrified until the fourth digit makes its ap- 
pearance. The chondrification of the coracoid likewise proceeds 
gradually from its center towards the mid-ventral. line. 
These observations agree with those of Braus (’09) on Bombi- 
nator. In this form there are no chondrification centers for the 
suprascapula and the epicoracoid. The epicoracoid of Bom- 
binator is homologous with the ventral portion of the coracoid in 
Amblystoma, which, as has been pointed out, chondrifies gradu- 
ally from the proximal part towards the periphery. 
The cartilage center for the humerus appears somewhat earlier 
than do those for the girdle. Considering the Amphibia as a 
whole, it can be said that in most cases this is true (Wiedersheim, 
’89, ’90, 92; Lignitz, ’97, and Braus, ’09). From Strasser’s (’79) 
description of Triton, one would assume, however, that in this 
form initial chondrification of the humerus and the girdle takes 
place simultaneously. 
The centers for the ulna and radius appear slightly later than 
those for the girdle, but they are completely chondrified before 
chondrification of the suprascapula and the coracoid have been 
completed. 
The greater part of the girdle remains cartilaginous throughout 
life, but the entire scapula and those portions of the procoracoid 
and coracoid which enter into the formation of the glenoid cavity 
become ossified. The cartilaginous suprascapula which, in the 
larva, is a long slender rod-shaped structure, elongates in an 
antero-posterior direction so as to become a broad flat plate. 
The procoracoid grows out in an antero-ventral direction and 
becomes a structure very similar in shape to the procoracoid of 
Necturus. The coracoid, which comprises the greater part of 
the ventral zone of the girdle, is a large flat rounded plate of 
cartilage lying ventral and posterior to the procoracoid. The 
two coracoids overlap in the mid-ventral line. The shape of the 
ventral portion of the adult girdle is very similar to that figured 
by Firbringer (73) for Salamandra maculata. 
