275 
THE STRUCTURE AND MECHANISM OE THE 
EUNNEL SURROUNDING THE MOUTH IN THE 
TADPOLE OE MEGALOPHRYS MONTANA 
By nelson ANNANDALE, B.A. 
I N a note added to Mr. Boulenger’s report on the Batrachia collected by 
Mr. Robinson and myself/ I remarked that the structure of the peculiar 
funnel surroundingthemouth in the tadpole of Mega/op brys montana,KuHL^ 
a toad belonging to the family Pelobatidae, presented certain features of interest, 
and I now propose to record my observations on its anatomy and mechanism, 
making no attempt, for which I have not the materials, to treat it as a 
developmental entity or to search out its affinities in more or less closely allied 
forms. It is worthy of note, however, that while the Pelobatidae produce 
other instances of growths of a similar nature, these growths are merely 
characteristic of certain species, and that whiltA^ egalopbrys Montana has the funnel 
well developed in the larva, there is no trace of it either in the adult of the 
same species or in the tadpole of 'Leptohrachium hasseltip Tsch.^ a form found 
in the same country under somewhat different conditions. It is not known 
at what stage in larval or embryonic life the funnel first commences to make its 
appearance in the former species, and all that I can say regarding its 
disappearance is, that in the young toad in which the tail is commencing to 
degenerate it is only represented by a small projection of the integument at 
the angle of the mouth on each side, whereas in the tadpole whose fore-limbs 
are just about to pierce the skin it is very nearly, but apparently not quite, 
as large in proportion to the rest of the body as at a slightly earlier stage of 
development. 
During life, the funnel is capable of assuming two very distinct forms, 
according to the position of the tadpole^ for the moment : — 
(i) When the animal is hanging from the surface film, as it frequently 
does, this structure becomes a translucent rhomboidal or lozenge-shaped 
float, depressed in the centre towards the mouth, but otherwise nearly flat. 
I. Antea, p. 132. 
2. Hanitsch, Rep. Raples Mm. Singapore, 1897, p. 8. 
3. A very fair representation of the tadpole is given by Dr. Gadow {^Amphibians and Reptiles^ p. 60), but by 
comparing it with photographs taken from life, I find that the funnel is represented as proportionately too small. 
