DEVELOPMENT OF THE SKULL IN THE BATRACHIA. 
201 
The vomers (v.) are rather small and edentulous, but are spiked both before and 
behind the inner nostrils ; their inner lobe is ear-shaped. 
This average Toad’s skull differs from an average Frog’s skull in several particulars : 
1. It is shorter, deeper, stouter, and altogether rougher; the endocranium is more 
solid, but scarcely more ossified, than in the Frog. 
2. The nasal region has the roof deficient, and the pro-rhinals pointed and turned 
inwards. 
3. The cartilaginous palatines are segmented, both from the ethmoidal wings, and 
the pterygoid cartilages. 
4. The palatine bones are cultrate, and the pterygoids are very broad, and bind 
down and fix the joint of the pedicle. 
5. The quadrate is partly ossified. 
6. The columella has an imperfect supra- and no inter-stapedial. 
7. The roof bones meet the squamosals over the temples. 
8. None of the bones bear teeth. 
56. Bufo melanost ictus. —Male, half-grown ; 2-| inches long (old specimens measure 
5 inches). India. 
The skull of this young individual comes very near to that of an adult B. vulgaris , 
and the skulls of old specimens almost rival the very large kind next to be described, 
viz. : B. agua; they are, however, very variable as to the degree in which the bony 
ridges are developed, some having their skulls much more crested than others. 
This is a very short, broad skull (Plate 35, figs. 7, 8), its length is only three- 
fourths of its breadth; the condyles of the quadrate (q.c.) reach as far back as the 
exit of the vagus nerve (X.). The occipital condyles ( oc.c.) are large, infero-posterior, 
and are separated by a narrow notch, which is the end of the basi-occipital synchon¬ 
drosis. The prootics and ex-occipitals ( pr.o ., e.o.) are confluent, and the bone half 
surrounds the optic fenestra (II.). The orbito-sphenoidal region ( o.s .) is cartilaginous, 
and occupies two-fiftlis of the orbital region. The auditory capsules are ossified as far 
as to the outside of the horizontal canals; but the tegmen (t.ty.) is cartilaginous, as 
also is the floor of the vestibule ( vb .). The girdle-bone (etli.) occupies its own 
(ethmoidal) region very exactly; the nasal territory ( n.r ., s.n.) is quite free from true 
bone. The form of the various parts is quite like what is seen in B. pantherinus. 
The palatine bones (pa.) are sub-arcuate, and on the left side there are two sub-equal 
bones. 
The pterygoids ( pg .) bind down on the pedicle ( pd .) ; the quadrate region is soft, 
the annulus ( a.ly.) perfect, and the stylo-hyal ( st.h .) confluent above. The stapes 
(figs. 9, 10, 11, st.) is oval and plano-convex ; there is a distinct reniform interstapedial 
cartilage (i.st.) ; the medio-stapedial ( m.st .) is a thick bony rod above, and is very 
narrow and decurved below. The cartilage proceeding from it has been almost 
MDCCGLXXXI. 2 D 
