Dr. G. Baur on Meiolania. 39 
Chelodina (Chelys not at hand). Besides, this would have 
nothing to do with the condition found in the Cryptodira. 
To explain this I give a description of the relations between 
preefrontals, palatines, and vomer in the Testudinata. 
In all the Cryptodira the prefrontals show two inferior 
processes: one which we call the inner process is connected 
with the vomer and the inner portion of the palatines; the 
other, the outer process, is connected with the maxillary, or 
may even reach the outer portion of the palatines. Between 
these two processes and the palatines and maxillaries we find 
the foramen nasopalatinum. 
a. Cryptodira. 
Chelydride, Dermatemydidx, Staurotypide, Cinoster- 
nide. 
Inner process of prefrontal in extensive connexion with 
vomer and palatines; outer process in no connexion with 
palatines. 
The Cheloniide show the same condition, but in some 
forms the connexion between the inner process and the pala- 
tines has gone. We may distinguish the following stages :— 
Huclastes.—Like Chelydride. 
Chelonia.—Inner processes clearly connected with palatines. 
Thalassochelys.—The ends of the inner processes touch the 
palatines. 
Colpochelys, Carettaa—No connexion between inner pro- 
cesses and palatines 
Dermochelydide.—Connexion still more reduced ; ends of 
inner processes touching vomer only. 
Emydide and Testudinide.—A similar condition to that in 
Chelydridze we find in some of the Emydide (Trachemys 
serrata, Ptychemys concinna and mobiliensis). In others the 
outer prefrontal process begins to touch the palatines (JJala- 
coclemmys, Chrysemys, Terrapene, Clemmys). Or in many of 
the Testudinide a strong connexion exists between this pro- 
cess and the palatines; hence the foramen nasopalatinum is 
formed by the preefrontals and palatines only. This foramen 
may be very much reduced and nearly disappear (Hmys 
meleagris, Clemmys guttata, different Testudinide, T. poly- 
phemus). 
8. Chilote, Wiegm.* 
The foramen nasopalatinum generally formed by pre- 
* T use the name Chilotz in preference to Gray’s name Trionychoidea, 
expressing only a superfamily. 
