183 
DEVELOPMENT OF THE SKULL IN THE BATRACHIA. 
and below, along a third, of the proper nasal territory. This extensive bony tract takes 
in the ethmoidal wings up to the proper facial ethmo-palatine (e.pa.), and uses up the 
small superorbital projections ( s.ob.). 
The roof and floor of the nose have the usual width; the latter narrows, crescentically 
at the middle, and the roof is widest behind. The septum nasi (fig. 11, s.n.) is thick and 
well marked, it ends in a distinct prenasal, to the sides of which are fused the horns 
of the roof crescents (on each side of s.n.). As in Hyla Ewingii (see Plate 31, figs. 2 
and 4, p.rh.), the pro-rhinals (fig. 12, behind px.) have the form and appearance of the 
angles of the primary cornua, and are half as large— a very unusual size. The append¬ 
ages of the nostrils (uE.uE.) are well developed ; these passages are at the average 
distances, outside the crescentic snout; the inner nostrils (i.n.) are large, circular, and 
their distance is one-fourth greater than that of the outer holes. The palato-sus- 
pensorials are in several respects varied from the norma ; the palatine portion is 
evidently stronger than the pterygoid, and the arch is angulated where these regions 
meet. The ethmo-palatine (e.pa.) narrows as usual where it joins the ethmoidal wing, 
and both this lessening, and the cessation of the bony deposit, mark off the true facial 
part. The pre-palatine is the point and edge of a dilated blade, and under this a 
large palatine bone ( pa.) binds, which is falcate and dilated externally, and has a 
cultrate ridge growing from its middle third— like an old tootli-bearing crest; as in 
Bufo cigua, Callula pulchra , Cystignathus ocellatus, and some others. 
The pterygoid bone (pg.) is slender, but strong; the re-entering angle of its fork is 
rounded, its inner fork {pel.) forms a suture with the skull, and ties down the carti¬ 
laginous pedicle, as in Hyla albomarginata (see Plate 32, fig. 7). The quadrate region 
is rather short, moderately retral, and considerably ossified ; the condyle ( q.c.) is a well- 
formed bi-cristate trochlea. There is a middle sized annulus ( a.ty.) ; its band is wide, 
leaving a small central space ; it is open above. The mandible (fig. 13) is perfectly 
typical, and the Eustachian opening (fig. 12) is oval and rather large. The stapes 
(fig. 15, st.) is large, oval, and knobbed; the medio-stapedial ( m.st.) is pistol-shaped, 
with a heavy “ handle” of cartilage, notched off from the bony part, and itself emarginate 
behind. The shaft is arcuate and very slender; it is followed by an extra-stapedial 
(e.st.) which is two-winged, and the wings are crenate. A bud grows from the middle 
of this oakleaf-sliaped plate, which ends as a free knob, behind, but from which no 
ray protrudes, as a supra-stapedial. 
The stylo-hyal (fig. 12, st.h.) is confluent above, and passes into a middle-sized tape 
(fig. 14, c.hy.) that ends in a straight hypo-hyal horn (li.hy.). 
The retiring part passes quickly into the base, for the “ notch ” is shallow ; so also 
the plate itself (b.li.br.) is of small extent, fore and aft, and has no front lobes, only long 
hinder processes. The large, expanding, highly ossified thyro-hyals ( t.hy .), diverge 
considerably behind; in front they are anchylosecl together, and there they form 
a “ basi-branchial ” bone (Jj.br.), whose wedge-like point nearly reaches to the selvedge 
of the emarginate basal plate. 
