98 
MR. W. K. PARKER OR THE STRUCTURE AHD 
The interorbital region is rather pinched than swollen in the middle, and gently 
narrows, forwards; from the hind margin of the optic fenestra (II.) to the front of the 
true ethmoidal region, half behind, is cartilage, and half, in front, is bony; the latter 
tract is the “girdle-bone” ( etli .). This bone has a convex fore, and a concave hind, 
margin; it nearly reaches the fontanelle above and spreads a little into the ethmoidal 
wings, right and left. There is no trace of a superorbital “ eave. ” 
The nasal region is normal as to its wide floor ( s.n.l .), gradually lessening, backwards; 
it has large pro-rhinals ( p.rh .); and it wants a pre-nasal rostrum ; but the roof (fig. 1) 
is very narrow, and the thick wedge-shaped end of the septum nasi ( s.n .) is ossified 
separately: this bone ( p.n.) is a low triangle, with its apex backwards. 
The large sub-oval orbital spaces, and the strongly bent bow of the palato-suspen- 
sorial are normal, but wider than usual; the pterygoid bone ( pg .), with the pedicle 
( pd .), are also normal; but the palatine bone (pa.) is composed of two sub-equal 
pieces. These are large in proportion to their cartilaginous model, and the outer 
piece is large and falcate. The quadrate hinge (q.c.) is normal; above it the quadrato- 
jugal (qj.) has ossified a good tract of the cartilage. In the rounded angle formed by 
the forks of the pterygoid the Eustachian passage (eu.) is of medium size, is oblique, 
turning outwards and forwards. 
The “annulus” ( a.ty ,) is broad, rather small, and imperfect above; the stapes 
(fig. 4, st.) is large, oval, sub-pedunculate, and obliquely emarginate on its antero- 
superior edge. 
The columella (fig. 4) is pistol-shaped, there is no interstapedial cartilage separate 
from the medio-stapedial; this bar is gently arcuate ( m.st .), and ends in a broadly 
spatulate extra-stapedial (e.st.) with a strong supra-stapedial (s.st.) confluent above. 
The mandible (fig. 3, d., ar., m.mk.) is perfectly normal, and so is the hyo-branchial 
apparatus; the stylo-hyal (fig. 2, st.h.) is articulated, above. 
The investing bones (figs. 1, 2) are on the whole similar to those of a Common Frog 
of the same size, but they are less solid. The parasphenoid (pa.s.) has a similar form, 
and so have the vomers ( v .); these, however, are turned outwards much more. The 
pre-maxillaries, septo-maxillaries, maxillaries, quadrato-jugals, and squamosals have 
the typical form, but are all rather feeble. 
But the fronto-parietals (f.p.) are very arrested ; and although they reach from the 
ethmoidal wings to the junction of the anterior and posterior canals ( a.s.c ., p.s.c.) they 
are each only two-thirds the width of the naked space between them. 
The contrasts between this and the typical skull arise mainly from the following 
characters:— 
1. There are no secondary fontanelles. 
2. The fronto-parietals are abortively developed, leaving the fontanelle largely open. 
3. The occipito-auditory ossifications, right and left, are generalised, and not properly 
divided into prootics and ex-occipitals. 
4. There is an “ anterior septal bone in the nasal region. 
