170 
MR. W. K. PARKER OK THE STRUCTURE AUD 
roofs are small (figs. 1 and 4), and the nasal floor large (fig. 2, right and left of s.n.). 
The end of the septum (s.n.) projects as a triangular rostrum (fig. 4, p.n.), and the paired 
trabecuke have developed their new horn or pro-rliinal (p.rh.) in such a manner as to 
almost rival the outer angle of the first horn (fig. 4, c.tr.) ; that is pedate with the toe 
outwards : this is like an adze blade. The outer nostrils (e.n.) are only moderately 
wide apart; the inner (i.n.) are not so far apart as in many cases ; they are very large 
and circular; the labials (u.l l .u.l z .) are normal. The palato-suspensorials are like those 
of a young Common Frog ; they are slender and but little affected by the bony tracts ; 
have a large cultrate pre-palatine; and end behind in two massive growths, the 
condyles of the pedicle and quadrate (pel., q.c.) ; these parts are much like those of 
Pelodryas. The Eustachian opening (eu,) in the angle is almost circular and of the 
average size—only half as large as the inner nostril. The palatines and pterygoids 
(pa., pg.) are slender, but quite normal. The mandible (fig. 3) is normal. 
The annulus (figs. 1 and 5, a.ty .) is of normal size, but its horns are wide apart. 
The stapes (fig. 5, st.) is an oval plate obliquely truncated in front; on it, antero- 
superiorly, the arched columella fits; it is equally wide at both ends, has no segmen¬ 
tation, and no supra-stapedial cartilage—only a fibrous band (s.st.). There is no 
inter-stapedial segment, even marked by ossification, and the bony matter runs up 
nearly to the stapes. The extra-stapedial (e.st.) is two-fifths the length of the outer 
rod ; it is a rounded spatula. 
The stylo-ceratohyal is confluent above (fig. 2, st.li.), and gently widens to the 
middle (fig. 3, c.hy.) ; it then lessens again, and returns backwards into the basal plate 
without any hypo-hyal lobe. Only the sharp postero-lateral lobe exists on the short, 
small basal plate (b.h.br.) ; the thyro-hyals (t.hy.) are well developed, moderately 
diverging, and straight. 
The investing bones are such as we should find in a young Pelodryas equal to this 
species in size. The fronto-parietals (fig. 1, fp.) form a narrow, straight wall-plate, 
widened, like a foot, over the temporal fossa ; they turn slightly outwards over the 
superorbital eave, and inwards, a little behind. The nasals (n.) are narrow crescentic 
shells, with a spike on the middle of their convex edge. 
The marginal bones ( px. , mx., q.j.) are well formed and typical, but extremely 
thin ; I find no septo-maxillary in tins species. The squamosals (sq.) have a good 
upper bar, projecting as a free postorbital process in front. 
The parasphenoid (fig. 2, pa.s.) is characteristic of this Family; it is well formed, 
wide in its main part, has all its processes pointed, but the basi-temporals are narrow. 
The vomers (v.) show nothing of the breadth of those of Pelodryas (Plate 34, fig. 2), 
nor the radiate character of those of Pkyllomedusa (Plate 34, fig. 8); they are quite 
normal, and have a small obliquely-oval dentigerous plate. 
This skull should be compared with that of a young Common Frog of the first 
autumn; then we can see that its divergence from the type is in these several pecu¬ 
liarities, namely:— 
