614 
ME, W. K. PAEKER ON THE STETTCTUEE AND 
shaped temporal (squamosal, fig. 7, sg.) in its upper part rides over the auditory mass, 
and sends forwards and outwards a postorbital process ; its handle is largely enclothed 
with the tympanic curtains ; but the lower end is apparent, overlapping both the qua- 
drate cartilage and its bony style. 
I have already described the lower hones of the gape ; there now remain the upper. 
The whole bony arch is thrown round the upper face, and reaches nearly to the quadrate 
by the jugal process of the maxillary. This bone gradually broadens to its fore part, is 
abruptly truncated in front, and sends upwards a process to articulate obliquely with 
the anterior edge of the descending crus of the nasal. The arcuato-oblong premaxillaries 
(px.) form a double keystone to the great arch ; they fit by straight surfaces to each 
other and to the maxillaries. The nasal process of the premaxillary (fig. 6, n.px.) is 
large and convex ; the palatine process is a short spur bounding the inner end of the 
emarginate posterior margin, below, as in the frog (op. cit. plate ix.). There remain two 
bones to be described : these are the “ cornets ” of Duges, my septo-maxillaries (fig. 6, 
s.mx., and “ Frog’s Skull,” plate ix.). Professor Huxley (art. “ Amphibia,” p. 754) did 
not observe them in JRana esculenta. 
In the Toad (fig. 6, s.mx.) they are unusually large and well developed ; in shape they 
are hippocrepiform, and, indeed, their likeness in outline is great to the shoe of a horse 
turned up for the frost, but the sides are largely connected by bony matter. The 
antero-superior labial (ul.V.) has its round inner end encased by the premaxillary, but 
the trihedral blade rests on the upper face of the septo-maxillary *. 
Structure of the Skull in Bufo vulgaris . — First Stage. Embryos one third of an inch 
(4 lines) long. 
At this stage the external Franchise are becoming short, and the internal are just 
developing. It corresponds to the third stage as given in my paper on the Frog’s Skull 
(plate iv. figs. 7-12). 
Before describing this stage in the Toad I shall show the weak points in the former 
paper. 
In the earlier stages (1 and 2) I find no error as yet; but the facial parts are 
coloured lilac, as though they were cartilage, when they are still only very solid indif- 
ferent tissue. 
In the figures showing the auditory sac the open membranous space is shown as though 
it were supero-lateral, whereas it is superior in position. 
In the third stage this is figured and described as filled in (plate iv. fig. 7, au.), w 7 hereas 
it is open for some time afterwards. In the same figure is to be found that mistake 
which became the parent of several more. The hyoid arch is figured as two cartilages 
* The term “ cornet,” or turbincd, is wholly inapplicable to this hone ; it answers to one of the “ preorbital 
series ” of a Ganoid or Teleostean (Siluroid) fish, and reappears, in a specialized form in relatio'n to the nostrils, 
not only in the Batrachia, hut also in Snakes and Lizards, where it has its fullest development, and in Birds, 
whose palato-nasal structures are metamorphosed to the utmost. 
