88 
MR. W. K. PARKER OK THE STRUCTURE AND 
The palato-suspensorial arches and their relation to the nasal region are like those 
of the fourth of my stages of Pseudis (see Plate 12). The “ ethmo-palatine” (e.pa.) is 
a thick transverse bar, whose flattened upper end articulates with the ethmoidal wall. 
The “pre-palatine” ( pr.pa .) is split into two laminae, the outer one is rounded, and the 
inner and upper lobe is sharp ; the outer runs into a second spike, turning inwards on 
the transverse bar (fig. 2). The “post-palatine” ( pt.pa .) now forms a crescentic crest 
on the top of the far-extended pterygoid cartilage ( pg .), where it turns inwards, in 
front. 
The former was free behind ; and its new and fixed position, as compared with its 
original condition, is well seen by comparing my third and fourth stages of Pseudis 
(Plates 11, 12). 
The rest of the arch keeps its even size as a rather wide band, until it forks; the 
short inner fork is the pedicle (pd.), the longer outer fork is the quadrate and its 
hinge ( q ., q.c.), which reaches to a line crossing the middle of the stapes ( st .). The 
palatine and pterygoid bones (pa., pg.) are normal: the former looks like the bone of 
an old individual; the latter is thin and arrested. 
The Eustachian openings (eu.) are large and turned obliquely outwards and for¬ 
wards ; the stapes (figs. 5, 6, st.) is an elegant oval, and has wedged inside its front 
margin a much smaller oval cartilage quite distinct—the interstapedial hind part 
of the columella. The main part of the columella ( co.) is not developed into regions; 
it is long, sinuous, and finger-shaped, with a crest near the stapes: but for the separate 
interstapedial, this columella would have corresponded with that of Pseudis at its 
fourth stage (Plate 12, fig. 6). The narrow “annulus” ( a.ty.) is arrested ; it is a knee- 
sliaped strap of cartilage bent forwards. 
The mandible and hyo-branchial plate (figs. 3, 4) correspond with those of a very 
young Frog; the mento-Meckelian is not finished, and the cerato-hyal ( c.hy .) runs 
short of the ear-capsule; there is no hypo-hyal lobe, and only the hinder part of lateral 
lobes. 
Nearly all the investing bones have the same arrested character; the parasphenoid 
(fig. 2, pa.s.) is, however, very large ; the vomers (v.) are small, angulated crescents, 
without teeth. 
The fronto-parietals fail to cover more than half of the great fontanelle; this cor¬ 
responds to what has been found in other species of this genus.* 
The deflection from the norma seen in this small skull is very largely due to arrest, 
on account of the small size of the species, and perhaps also to a somewhat immature 
state. These deficiencies, as compared with the skull of an adult of the common kind 
are :— 
* Professor E. D. Cope —“ Eleventh Contribution to Herpotology of Tropical America,” Amer. Phil. 
Soc., June 20th, 1879, p. 264—says that Letuperus (a synonym of Gompliobates ) has an open fontanelle. 
