DEVELOPMENT OE THE SKULL IN THE BATRACHIA. 
233 
Fourth Family. “ Phrynischle.” 
Toes webbed; sacrum broad; no parotoids; ear generally very imperfect. 
Genus Phryniscus. 
68. Phryniscus cruciger .—Adult male; 1 } inch long. Interior of Brazils. 
The small skull of this species (Plate 41, figs. 1-5) has its breadth one-thirtieth 
greater than its length; its outline, up to the hinges for the lower jaws, is nearly 
triangular, but the extreme end of each hinge (q.c.) is opposite the centre of the Eusta¬ 
chian opening (eu,), so that much of the skull—all the hind skull—lies behind the 
facial margin, as in newly metamorphosed Anura of a high type. 
The whole skull has the appearance of an abortively developed Bufonine structure, 
with an abnormal amount of ossification; it is like a badly developed skull of such 
a form as Bufo ornatus, or of the half-grown Otilophus (Plate 37) ; moreover, it is 
asymmetrical to a degree very seldom seen in the group ; more so than that of Siredon 
among the Urodeles. The foramen magnum (frn.) is large and obliquely superior; 
the occipital condyles ( oc.c .) are large, sub-pedunculate, and directly posterior. Out¬ 
side them, the epiotic and tegminal projections ( p.s.c ., t.ty.) are a little and a little 
further forwards, and yet, on the whole, the large hind skull is a broad transverse 
tract, the “canals” standing out of it well, and the wide tegmina, bounded by the 
squamosals (sq.), enlarging gently, forwards. Two-thirds of the tract beyond the 
horizontal canal ( h.s.c .), on each side, is cartilaginous; from the hind margin of the 
optic fenestra (II.) to a distance twice the extent of that space there is cartilage; and 
the snout ( p.n .) in front of the nasals ( n .) is also soft. 
The rest of the cranium proper is bony, and in some parts these extensive ossifica¬ 
tions are anchylosed to the investing bones. 
Measured along the axis, the three regions are sub-equal; they are all very broad; 
and, taking in the face, the outline becomes just less than a right angle; for the 
proper cranial margins run inwards rapidly from behind, forwards. The temporal 
region is of great breadth; the orbital edge is concave; the main fontanelle (fig. 1), 
contrary to wont, is widest across—like a Tortoise’s heart; near it, behind, the other 
two spaces are large and circular; the larger space is not quite covered. 
The girdle-bone ( eth .) leaves only a small orbito-sphenoidal tract (o.s.), behind, and in 
front runs to the fore edge of the nasals (n.) above (fig. 1), and to the premaxillaries 
below (fig. 2, px .); it takes in the “ wings,” above, and the palatine flap, also, below ; 
moreover the palatines are anchylosed with it (figs. 1, 2, ep.a., pa,), the bony “alee” 
touching the pterygoids ( pg. ) ; the vomers (r.), also, are confluent with the large 
girdle-bone. 
The nasal roof and septum (figs. 1-3) are formed into an over-hanging decurved beak, 
with a sinuous outline ; this pre-nasal {p.n.) is a mere thickening of the middle part, in 
front, as in the embryos of many Yertebrata at an early stage ; this arrested (or gene- 
mdccclxx xi. 2 ir 
