DEVELOPMENT OF THE SKULL IN THE BATRACHIA. 
219 
3. In the curious porcine form of the snout, broad and overhanging the facial bones. 
4. In having no teeth, either marginal or submarginal. 
5. In the fixity of the pedicle. 
6. In the breaking up of the palato-suspensorial cartilage. 
7. In the fixity of the stylo-hyal and the supra-stapedial, and in distinctness of the 
stapedial “ boss.” 
8. In the narrowness of the basal plate, and the absence of hypo-hyal lobes. 
9. In having a second pre-orbital besides the septo-maxillary. 
Second genus. Otilophus, 
G3. (A) Otilophus margariti/er. —Half-grown female ; 1-J inch long. Venezuela. 
This skull is about one-fourth less than the last; it resembles it very much, but is 
feebly ossified (at present), has a wider roof, and more ornate and crested bones, 
externally. If this skull had been arrested at this stage there would have been no 
reason for the sub-generic distinction Otilophus , as distinct from Bufo. I agree with 
that distinction, but would put B. ornatus into the sub-genus. 
We have here the same triangular broad roof, and high skull (Plate 37, figs. 5-7), 
as in the last, but the occipital region projects more, behind, and the snout is much 
narrower, and more rounded ; moreover the investing bones are very ornate with 
small beads or pearls of clear bone. The figures (Plate 37, figs. 1-4 and 5-10) will 
give a clearer idea of the great likeness and small unlikeness of these two exquisite 
little skulls. The occipital condyles ( oc.c .) are large, reniform, and postero-inferior ; 
they are separated by a rounded notch half their own width, and they show, more than 
those of the last kind, that the motions of the head on the atlas are very free, and 
worked by strong muscles. 
The ex-occipitals (e.o.) are less than half the size of their region ; and both above 
and below are separated by wide tracts of cartilage. The floor of the vestibule 
(fig. 6, vb.) is naked cartilage ; the top of the ear-sac is all covered, except the epiotic 
region (ep.), so that the prootics are only seen where they surround the foramina 
ovalia (V.). The prootic region is wide, unossified, and forms a large tegmen ( t.ty .) 
under the squamosals ( sq .). The large optic fenestrse (II.) are surrounded by carti¬ 
lage which occupies two-thirds of the orbital region (o.s.) ; this part is of almost equal 
width, but widens at both ends ; its depth is very small (fig. 7), but it bulges in the 
middle. The limited girdle-bone (eth.) is complete below (fig. 6), and takes up its 
own proper cartilage ; above (fig. 5), it only appears just where the roof-bones partly 
expose it as a circle of bone reaching the septum nasi in front, and the fontanelle 
behind, but it has much cartilage on each side. The main fontanelle is rather small, 
and elegantly heart-shaped ; the secondary fontanelles are large and oval ; the 
“ tegmen cranii ” is largely developed and the endocranium is rather massive. 
The narrower and more rounded snout is extremely porcine ; the outer nostrils are 
very large and not far apart; the large round inner nares (fig. 6, i.n .) are tw T ice as far 
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