132 
MR. W. K. PARKER ON THE STRUCTURE AND 
This skull (Plate 24, figs. 1, 2) is short, flat, and a very delicate semi-osseous 
structure altogether; the length is to the breadth as 5 to 6, and the quadrate 
condyles (q.c.) reach as far back as the fore edge of the stapes. The occipital 
condyles (oc.c.) are large, separated by a very gentle emargination of the basal plate, 
and directly posterior in aspect. 
The auditory regions are greatly winged outwards, becoming narrow externally; the 
common occipito-auditory bones are single on each side, reach as far out as to the 
wings of the parasphenoid below, and touch the narrow squamosal above; thence 
the outside of the vestibule ( vb .) and the tegraen tympani ( t.ty .) are left soft. 
So also is a rather wide tract above and below at the middle; whilst in front the 
prootic region of the bone reaches the foramen ovale (fig. 2, V.), which it half encloses. 
The optic fenestra (II.) is large, and is well surrounded by cartilage, and this cartilage 
is continued beyond the middle of the orbital territory; two-fifths of this territory 
only is taken up by the girdle-bone ( eth .) This bone just reaches the “wings” and the 
fore end of its own proper territory, and above (fig. 1, eth.) it is imperfect; the right 
and left half, which are united, but leave emarginations below (fig. 2), are not fused 
above : their horns just meet in the fore margin of the anterior fontanelle (fo.). The 
“tegmen cranii ” is very short in the ethmoidal region; it forms a flat and widish wall- 
top, runs a band across the roof in the postorbital region, and becomes superoccipital 
in front of the middle of* the auditory regions, right and left. The main space thus 
spanned is divided into two fontanelles (fo.,fo'.) ; the front space is one-third larger 
than the hinder, and is emarginate behind; the hinder space is transversely oval. This 
is a rare modification; behind, there are, as a rule, two secondary spaces, and in 
several types none. 
The tegmen grows out into a small superorbital “ eave ” in front, and then there is 
a wide stretch of cartilage—ethmoid and ethmo-palatine. Outside the small super¬ 
orbital projection of the “wing” there is a very large superorbital cartilage ( s.oh '.); it 
covers nearly a third of the orbital space ; is roughly oval, its large end foremost, and 
it is placed obliquely, with its hollow face downwards. This is also a rare character, 
it occurs in Phyllomedusa tricolor; but in that type it is much smaller. The common 
septum of the ethmoidal and nasal regions (fig. 1, s.n.) is large, and is continued in 
front as a prenasal rostrum ( p.n .). As in Bombincttor the aim of the nasal roof (fig. 1) 
are very little developed along the sides of the septum, the cartilaginous pouches 
being nearly all in front, lying on, and coalesced with, the “ subnasal laminae.” These 
plates (fig. 2, s.n.l .) are normally wide, and have long narrow pro-rhinals ( p.rli .). 
The muzzle being very obtuse, the nostrils are wide apart, they are protected by 
the usual inner and outer labials (uP.u.l 2 .), which are large and well developed. 
The palato-suspensorial arches are wide apart, and the orbital spaces are oval, the 
pre-palatine spike ( pr.pa .) is large, the stem (e.pa.) wide, and the post-palatine and 
pterygoid tracts are but little affected by the palatine and pterygoid bones (pa., pg.), 
wffich are quite typical. This cartilage is seen in both forks—the pedicle (pc/.) and 
