136 
MR. W. K. PARKER OK THE STRUCTURE AND 
The wide contrast between this skull and that of Alytes is seen at a glance by a 
comparison of the figures ; it differs from the “norma” in the following particulars : — 
1. The skull, as a whole, corresponds with that of a young specimen of the typical 
kind. 
2. The occipito-auditory region is quite ossified, showing no distinction of front and 
hinder centres. 
3. The skull, proper, is very broad behind, and largely unossified in the interorbital 
region, the girdle-bone being imperfect above. 
4. The annulus and Eustachian tubes are small. 
5. The stapes is very large, projecting, and bony. 
6. The columella is arrested ; there is no inter-stapedial segment or ascending process. 
7. The stylo-liyals are confluent above. 
8. The premaxillaries are grafted on to the 1st upper labials. 
9. The vomers are very small and toothless. 
Note—That the highly ossified hind part of the skull is in great contrast with the 
feebly ossified fore part; the large size of the stalked stapes is in great contrast with 
the arrested columella and the feeble annulus. 
Sixth Family. “ BoMBlNATORlDrE.” 
Genus Bombinator. 
33. Bombinator igneus. —Adult female ; If inch long. Europe. 
The semi-oval skull is of the average form; the length is as to the breadth as 
7 to 8, and the quadrate condyles reach to a point opposite the fore edge of the 
stapes; in Alytes they were opposite its fore edge, but the breadth of the skull was 
much greater. 
This and the next type have many things in common, but their skulls are in strong 
contrast, on account of the feeble ossification of the one, and the unusual degree of 
hardness attained by the other; the contrasted figures will show how they differ 
(Plate 25, figs. 1-4, and 5-11). 
The main difference in form of outline between the skull of Bombinator and that of 
the Common Frog, is that in the former the snout is much wider; the interorbital 
region is much alike in both, it is rather narrow, lessens from before, backwards, and 
bulges gently in the middle. 
The auditory region is also wider, and the whole skull more archaic, and also much 
arrested. 
The occipital condyles ( oc.c .) are separated by an interval their own breadth, and 
but little emarginate ; they are supero-posterior in position as in Pip a. wdiich is a rare 
modification. The roof over the foramen magnum is also gently emarginate, and both 
in roof and floor the bones (e.o.) are divided by a moderate wedge of cartilage. 
