398 TRANSACTIONS OF SECTION D. 
The following Papers and Reports were then read :— 
1. Plankton. By Professor Herpuay, F.R.S. 
2. Hxhibition of Lantern Slides of the Narwhal and Beluga. 
By Professor H. JUNGERSEN. 
8. Some Notes cna Collection of Australian Frogs. 
By J. Bootu, M.C.H., B.Sc. 
The work of which this paper is the outcome was undertaken in the hope 
of finding some method of determination and identification of Batrachian 
species, without resort to the slight dissection necessary to examine the sternal 
apparatus and the sacral vertebre. The materia! made use of was the col- 
lection of frogs at the Melbourne University, together with some of the speci- 
mens from the National Museum, and a few privately collected. 
In accordance with this original intention, stress was laid on external shape, 
and in order to render the description of shape more definite the particulars 
were expressed as far as possible numerically and in proportional measurements. 
The length of the specimen, from snout to vent, was taken as a basis, and 
other dimensions expressed in terms of it. © 
To facilitate these measurements, a scale was devised, by which the length 
of the specimen in millimétres, and other dimensions in proportional units, 
could easily be read off from the callipers. The particulars selected as most 
satisfactory for measurement were :—The depth of the chest; the length and 
breadth of the head; the length of the snout; the distances from eye to nostril, 
and between the nares; the diameter of the orbit; the width of the upper 
eyelid; the distance between the orbits; the diameter of the tympanum, and 
distance from tympanum to eye; the length of hind limb; and the length of 
the digits of the hand. These dimensions have been tabulated for a large number 
of specimens. 
It was found that the description and measurement of external features 
could not replace observations of the skeletal girdles, the variations in which 
seem to be of paramount genetic significance; while the external configuration 
and aspect is more related to the mode of life of the animals, and largely 
corresponds with the classification into:—swimming, climbing or tree, and 
burrowing or cryptic frogs. 
In the course of the work the relative value of the external characters 
came under review. Of these, amount of webbing on the toes seems to have 
been overrated, Professor Spencer having pointed out how very variable this 
character is in several species collected by him in the interior. Colour and 
markings are very definite in some cases, remarkably variable in others; but 
usually varying in such a way as to suggest a normal form from which the 
rest may be derived. This normal is probably to be found in strongly marked 
young specimens. Of particular markings, the vertebral line, in some species 
constant, in others, though normal, varies in distinctness to total absence, and 
again in others is very definitely present or absent. Another normal marking 
is the lateral face-streak, and nearly all face colourations may be considered 
as variations of this. An external feature closely connected with habit is the 
adpression of the thigh to the groin. In some species this gives rise to a 
difference of colour and texture in the concealed parts, while in others the 
groin is fully exposed and does not differ from the general surface. 
With regard to classification, the scheme of the British Museum Catalogue, 
as applied to Australian frogs, becomes reduced to three families of the 
Arcifera, Cystignathide, Hylide, and Bufonide, and (on account of the record 
of three species of the genus Austrochaperina, Fry) the family Ranide of the 
Firmisterna. 
A list of the Australian species, with references to descriptions and notes 
on the specimens examined, and tables of the proportionally measured dimen- 
sions, were appended. 
