558 De (CO. (GASTB: 
and overlap each other from before backward. Two specimens show 
the presence of these plates in the position of the restoration, but 
there are no traces of others on the sides of the ribs or on the sum- 
mits of the neural spines. 
The position of the plates below the scapula is anomolous but there 
seems no escape from the conclusion that they are restored in the 
natural position; if the 
animal was very broad 
and low, grotesquely so, 
then the pectoral girdle 
might have touched only 
the outer ends of the ribs 
and the plates might 
have lain above the 
girdle; but the condition 
of the specimen forbids 
such a conclusion. The 
pectoral girdle is excep- 
tionally well preserved 
Fic. 2.—Six anterior dorsal vertebrae of Dia- 
; me and free from distortion, 
dectes, sp., showing the form and position of the h lol 
plates overlying the ribs. Specimen No. 1075, the bones are ee yy 
University of Chicago collection. 4. ~ articulated and in their 
proper positions; the 
whole pectoral girdle has the form of a narrow U with the bottom 
forward. In fact the animal was distinctly narrow chested. There 
seems no possibility that crushing could have forced the plates into this 
position. ‘This is perhaps one of the greatest arguments against the 
position of the Diadectids as ancestral to the turtles. Cope describes 
the pectoral girdle of Otocoelus and Conodectes as internal to the 
dermal plates which are however much larger proportionally than 
in the Diadectids. 
The assemblage of characters shown in the restoration seems to 
bear out the suggestion made in the previous paper (Joc. cit.) that the 
Diadectids are perhaps the nearest to the turtles of the forms now 
known. The powerful head and jaws, with their numerous testudi- 
nate characters, the strong thoracic guard formed by the great scapula 
with its clavicle, cleithrum, and interclavicle; the short, powerful 
