G8 
MR. W. K. PARKER ON THE STRUCTURE AND 
half- grown—or equal to the size of the full-grown individuals of this species. The 
parasphenoid (pa.s.) is very large, both in its main part and wings; this form is like 
that of the Common Frog, but the point is longer and sharper. 
The vomers ( v .) are typical; the septo-maxillaries extremely small if present, and the 
bones of the outer face normal, but slight. The nasals (n.) are long crescentic shells of 
bone; the fronto-parietals (f.p.) are large and out-spread over the hind skull and then 
become gradually fine sharp styles in front, leaving part of the girdle-bone and a little 
of the fontanelle (fo.) uncovered. 
The “ frontal suture ” is permanent; the “ sagittal ” is filled in with bone ; the two 
sides being continuous over the inter-auditory region. 
The mandible (fig. 3) is quite normal. 
The stylo-hyal end of the hyoid band (fig. 2, st.h.) is distinct and pointed as it 
passes behind the Eustachian opening ; this band widens to double its breadth (fig. 3, 
c.hy.) in the lower half, and then turns suddenly round to join the basal plate ( h.liy ., 
Mi.br.). 
Round the outside of the broad distal half there is another band of cartilage as wide 
as the upper half of the main band. 
This is an “extra-hyal” element (ex.hy.) ; it passes over the hypo-hyal loop as a 
short hook. 
Other Oriental Batrachia show this, but not so distinctly, e.g., Tomopterna, 
Calkda, and Diplopelma, and the Australian Tree-frogs have a rudiment of it : here 
it is most largely developed. 
If this cartilage be compared with the pectinate “ inter-branchial ” of Chimcera 
(Hubrecht, fig. 2), it will be seen to correspond with the base of that comb-like 
cartilage. 
In Tadpoles the extra-branchials send pectinate processes inwards, but they show 
no separation of the extra-branchial bands from these “rays” of the septa, such as 
we see in Sharks, for the branchial apparatus of the Tadpole is as highly generalised, 
as that of the Shark is intensely specialised. 
The “spiracular cartilage” belongs to the suspensorium ( of the 1st arch), and becomes 
utilised as the annulus tympanicus ; this rarer “extra-hyal” and the four extra- 
branchials all belong to one category. 
This infero-external element of the hyoid arch, like the supero-internal (epi-hyal or 
“columella ), does not appear until after the metamorphosis of the Tadpole; that is 
utilised as part of the apparatus of the fast-improving ear; the extra-hyal merely 
serves as an additional platform for the thin fan-like muscles of the throat. 
The rest of the hyo-branchial structure is quite normal; the lateral lobes are highly 
developed, and the thyro-hyals strong (fig. 3, t.hy.). 
Besides the remarkable shape of this skull, so wide behind and so pinched in in 
front—necessarily modifying the form of the investing bones—we have the subjoined 
differences from the typical form, viz. :— 
