936 THE AMERICAN NATURALIST. [Vow. XXXII. 
Case has figured one of them and referred to it in his descrip- 
tion on page 382. He has, however, scarcely done it justice 
when he refers to it as a thin ossicle. Fig. 1, here presented, 
gives a lateral view of this ossicle and of the seventh and eighth 
neuralia on which it rests. The figure is of the size of the 
object. 
The drawing that I made of the carapace, seen from above, 
is slightly different from that of Dr. Case, and I here reproduce 
such part of it as pertains to the bones involved (Fig. 2), one- 
half natural size. It is my opinion that Case 
has made the fifth and sixth neuralia exchange 
places in his drawing. My reasons for so think- 
ing are these : On the anterior end of neural 7 
of Case’s figure (9, according to his notation) 
there is an excavation that is not filled up as he 
has placed the bones; while as I have placed 
them, this excavation is accurately filled by a 
process from my neural 6. Again, Toxochelys 
evidently had, like its relatives, Thalassochelys 
and Chelydra, a system of epidermal scutes. 
Now, in these last-named genera, and in the 
great majority of other turtles, the suture im- 
pressions of these scutes cross the first, third, 
fifth, and eighth neuralia. The exceptions are 
rare. According to Owens’s! figure, the suture 
between the fourth and fifth scute passes across 
behind the eighth neural. Now, as I have arranged the neuralia, 
the dermal sutures are in their proper places. Another suture 
would probably cross just behind the ossicle lying across the 
suture, between neuralia 7 and 8. 
At the anterior end of neural 5 there is an excavation which 
had evidently served for the reception of an ossicle like the 
one across neurals 7 and 8; and in the collection there was 
then a bone like the ossicle referred to, and it quite accurately 
fitted the excavated surface. At that time there was no doubt 
that those bones belonged as they were drawn. There was 
also in the collection another bone, which I have figured as the 
1 Owen. Anat. Vert., vol. i, p. 61. 
Fic. 2. x 4. 
