146 EDWARD B,. POULTON. 
been done consisted of (1) parts of the bill hardened in chromic 
acid by the late Professor Moseley in 1874, at the same time 
that he prepared the tongue which I have described in this 
journal (see ‘ Quart. Journ. Micr. Sci.,’ July, 1883, p. 453, 
for further details concerning this material), and the horny 
teeth (see ‘ Quart. Journ. Micr. Sci.,’ July, 1888, pp. 31, 32) ; 
(2) a specimen kept many years in spirit in the Oxford 
University Museum, the ovary of which was described in this 
journal (January, 1884, p. 118); other similarly preserved 
specimens in the Museum were also employed; (3) the young 
Ornithorhynchus of which I was enabled to describe the true 
teeth through the kindness of the late Professor W. K. Parker 
(‘ Quart. Journ. Micr. Sci.,’ July, 1888, pp. 10, 11). This 
latter specimen was 8°3 cm. long in the curled-up attitude in 
which I received it, and the larger hairs had alone appeared 
above the skin. 
Since the above was written I am enabled, through the 
kindness of Professor W.N. Parker, to supply figures of the 
natural size of the young specimen of Ornithorhynchus referred 
to above. The appearance from the left side is seen in Plate 
15a, fig. 1, from the ventral aspect in fig. 2. ‘The latter 
has been already published, reduced one half, by the late 
Professor W. K. Parker. The drawings from which Pl. 15a 
was prepared were made by Mr. M. P. Parker. The considerable 
amount of work which has been already published upon material 
from the single specimen here figured is indicated in the 
following list of memoirs : 
G. B. Howrs.—‘ Journ. Anat. and Physiol.,’ 1886, xxi, p. 190. Describes and 
figures the shoulder girdle. 
G. B. Howes.—‘ Journ. Anat. and Physiol.,’ 1892, xxvii, p. 543. Describes 
_the pelvis, and figures a section of it. 
The late W. K. Panker.—‘‘ Mammalian Descent,’ London, 1885. Describes 
some of the external characters (p. 48, et seq.), and figures the ventral 
view of the specimen one half the natural size (p. 25). This same 
view is represented the full size in Pl, 15a, fig. 2, accompanying this 
paper, 
