1865.] LETTER FROM DR. J. KIRK. 227 
is 9’; the outer side of the same, parallel with the diameter of the 
shaft, 6", and the outer curve of the same process 10’. Breadth of 
the olecranon at middle 4"; the same tangentally at the neck and 
its circumference 15". 
The five carpal bones have a very considerable thickness in rela- 
tion to their breadths, and each has five articulating facets. The 
comparative superficies of three of these taken separately are, of one 
of them in length and breadth 33" by 3", thickness 13"; of a second 
3" by 3! in diameter, and 23" thick; of the third 3 by 2", and 22" 
thick. The metacarpal bones and phalanges are so imperfect and 
badly mounted that no dependence can be placed either on their 
number or position. 
The hyoid bone presents no marked divergence from the shape 
usual in Physalus. The body is compressed and with an anterior 
convexity. The anterior cornua are W-shaped, and with a moderate- 
sized notch, which is more pointed and narrower than in Sibdaldius. 
The thyrohyals are large, and thrown backwards from the body as 
much as 8 inches at their tips; they are thickest at their middle, 
and abruptly truncated at their extremities: these also differ from 
those of Siébaldius both in general thickness and in the direction 
in which they are produced from the body of the bone. The mea- 
surements of the hyoid are the following :—Greatest width in a 
straight line 34", and following the outer curve 39"; greatest length 
from before backwards 103". Length of body to fork of cleft 72! ; 
breadth of the body 6". Small or anterior cornua, in length 31".. 
Greater cornua (thyrohyals), breadth tangentially at the roots 6! ; 
circumference at same 13", and at their tips 9. The whole bone 
is light in comparison with its size. 
The pelvic bones are wanting. 
February 28, 1865. 
Dr. J. E. Gray, F.R.S., in the Chair. 
Mr. Fraser exhibited two eggs of the Rose-crested Cockatoo 
(Cacatua rosacea, Lath.), which had been laid a few days since by 
a bird in captivity, being, as he believed, the first record of the 
kind. Mr. Fraser remarked that the bird was very tame, and a 
good talker (thus answering the oft-repeated inquiry whether hen 
Parrots talk), and that his friend, William Goodwin, Esq., also had a 
very good talking Lesser Sulphur-crested Cockatoo (Cacatua sul- 
phurea, Gmel.), which had laid two eggs in 1839. 
A letter was read from Dr. John Kirk, Corresponding Member, 
containing the following reply to the observations of Dr. W. Peters, 
Foreign Member, in the ‘Society’s Proceedings,’ 1864, p. 377, rela- 
ting to Gerrhosaurus robustus :— 
