204 
MR. W. K. PARKER ON THE STRUCTURE AND 
is a very massive and wide liar, it is sigmoid, bending backwards towards the oval 
Eustachian tube (eu.), and then growing directly inwards to articulate with the basi¬ 
temporal bar of the parasphenoid ( pa.s .), whose end is, contrary to rule, most extended 
at the hinder angle. These binding bars hide all but the hinder half of the vestibular 
floors below ; they are sub-parallel with the palatine bars. 
The condyle of the quadrate (q.c.) is a trochlea, grooved obliquely ; the bar above it 
is largely ossified (fig. 3, q.) ; its height, from the otic process, which is covered by the 
squamosal (sq.), is very great for a Batrachian ; this Toad has almost the deepest face v 
of any of its Order. 
The mandible (fig. 3) is normal; none of its processes are large, but it is of con¬ 
siderable thickness, and only moderately ossified; the rod (mk. ) is continued forwards 
undiminished from the reniform condyle which lies in the grooved articulare (or.). 
The mento-Meckelian rod ( m.mlc.) is rather large, and the dentary (d.) is three-fifths 
the length of the entire ramus. 
The “ annulus ” (fig. 4, a.ty.) is only of a medium size, and narrow ; but it is com¬ 
plete. The stapes (figs. 4, 6, st.) is lozenge shaped, and has a boss for muscular 
attachment ; it is followed by an equally large segment, the distal half of which is 
ossified ; this is the inter-stapedial (i.st.). The next segment is the medio-stapedial 
bone (m.st.); it fits obliquely under the first, is slightly arcuate and slender, and ends 
in a thick spatulate cartilage, the extra-stapedial (e.st.), which sends upwards a supra - 
stapedial band ( s.st .), that is confluent above. 
Both the stylo- and hypo-hyal regions are absorbed, (figs. 2 and 5) and the cerato- 
hyal (fig. 5, c.liy .) is a sigmoid band, sharp at both ends. 
The front notch of the basal plate (b.li.br.) is deep and the plate itself rather narrow, 
with an angular projection on each side, behind; the thyro-hyals ( t.liy.) are large, 
bent, and divergent. 
The edges of the basal plate are thickened, and run in front into sharp horns ; the 
“ anterior lateral lobes ” are large, distinct cartilages, narrow in front, and dilated 
behind ; the hind lobes are absent. 
The roof is almost as complete as in Calyptocephalus (Plate 21), but it is formed of 
thick rough slabs, the large fronto-parietals, which are thrice the breadth of the top of 
the endocranium. 
Their edges, like the edges of all the surface-bones, are very thick; they reach 
within a short distance of the foramen magnum, and send out on each side a square 
postorbital process to articulate with the corresponding squamosal (sq.). 
The whole dorsal region of the skull is a shallow trough, through the raising of the 
edges; this is divided by the sutural line along the middle, which is complete from end 
to end. More than a third of this suture is nasal, the rest fronto-sagittal ; the fronto- 
parietals project furthest at the middle, and the nasals form almost half the orbital rim. 
Them pre-orbital process (figs. 2, 3, n.) is immense, and an ingrowth there would make 
them correspond to those of the Tortoise. Besides forming a wide foot to rest upon the 
