240 
MR. W. K. PARKER OK THE STRUCTURE AND 
closest to the Neotropical Toads, with ornate skulls, but lie down below them, being 
more generalised, and they are evidently abortively developed. 
These skulls form a great contrast to the Ranine “ normathe main differences are 
as follows:—- 
1. The skull is below the average size, bears no teeth, and its ossification is 
excessive, and generalised. 
2. There is much asymmetry in both the suspensoria, and the investing bones. 
3. These latter are in several cases anchylosed to the endocranium ; and in two 
species the palatines and vomers also. 
4. The snout is very wide, and has a generalised rostrum. 
5. The lower jaw is hinged to the head in front of the hind skull. 
6. The tympano-Eustachian cleft is merely a small blind slit. 
7. There is no “ columella ” nor “ annulus,” in two out of the three kinds, and in 
the third they are very small and arrested. 
8. There are no septo-maxillaries, and the maxillaries either only touch the very 
small quadrato-jugal, or run short of it by a considerable space—as in the Aglossa. 
9. The basal plate is very long and narrow, and has no hinder lateral lobes. 
10. The left maxillary and nasal are less than the right (and sometimes the right 
nasal is the larger bone), and the parasphenoid is less than half the length of the skull. 
Altogether, these may be said to lie at the very outside of their own sub-division, 
from the higher types of which they differ almost as much as the Aglossa; their place 
is between the ornate Toads and Hylaplesia. 
Fifth Family. “ Engystomid^e.” 
Ear rather imperfect; sacral apophyses dilated ; toes free ; no parotoids. 
Genus Engystoma, 
71. Engystoma carolinense. —Adult male; 11 lines long. Florida, 
This is another very instructive instance of a small arrested skull (Plate 43, 
figs. 7, 8), the length and greatest breadth of which are equal, and of the hinge of the 
jaw being in front of the foramen ovale (V). Here the face forms a triangle, truncated 
in front, the moderately broad snout being transverse. This form makes the relative 
size of the hind skull very large, and yet the parotic processes are small; the occipital 
ring, and the auditory capsules are unusually wide—more than in the newly meta¬ 
morphosed young of typical kinds. The occipital condyles ( oc.c .) are large and 
posterior, they are separated by a space one half larger than their own breadth. The 
synchondrosis is rather wide, above and below, and there is an endosteal rudiment of 
both basi- and supraoccipital (b.o., s.o.). 
