XVIL. On the Structure and Development of the Skull in the Crocodilia. 
By W. XK. Parxer, F.RS., P.ZS. 
Received October 15th, 1881, read January 17th, 1882. 
[Puares LXII. to LXXI.] 
Introduction. 
SEVERAL years ago I received from my friend Mr. David Bartlett several ripe young 
embryos of a Crocodile, the species of which was undetermined. Other ripe embryos 
of Crocodilus acutus (from St. Domingo) were about the same time given to me by 
another friend, Mr. Henry Power, F.R.C.S. 
' For about twelve years no further addition was made to my collection, nor further ob- 
servations recorded than such as were done, partially, soon after receiving these treasures. 
But early in the summer of 1879 I received from my talented young friend, 
Mr. Henry F. Osborn, of Princeton, U. S., a box of the eggs of Alligator mississipensis. 
These had been laid quite recently, and contained nothing sufficiently advanced 
for my purpose; but soon afterwards, when this failure had been made known 
to Mr. Osborn, I received another box of eggs. These reached me on August the 
8th; they were twenty-six in number, and all but one of them yielded me embryos. 
These have served me for my earlier and most important stages; but the largest 
embryos were scarcely half ripe. 
Shortly afterwards I received a large number (several dozen) of embryos of Croco- 
dilus palustris’, from Dr. Kynsey, P. M. O. of the Hospital, Colombo, Ceylon, who 
took great pains for me, employing his native assistant, Mr. S. Waytialingam, to collect 
them. This zealous service I owe to the influence of Sir Joseph Fayrer. An account 
of the nest-rifling of these “fearful wildfowl” has already appeared in the ‘ Proceed- 
ings’ of this Society (1880, pp. 186, 187). There were about eighty of these 
embryos, ranging from 13 to 10 inches in length; they were most carefully preserved 
and tabulated. 
I have no dates in the case of the embryos of the Alligator, and I can therefore only 
give measurements; but in the Crocodile embryos the time is given in each case, and 
this in specimens taken from two places, namely, Vadunakaloo and Talavaikal ; the eggs 
from both these sources were evidently laid about the same time. Mr. Waytialingam 
says that they are laid as early as June; and as the smallest specimen measured nearly 
2 inches in total length, and was taken on the 16th of July, it is probable that both 
the nests were filled by the middle of June. They were ripe on the 8th of September, 
1 See Giinther’s ‘ Reptiles of British India,’ p. 61, pl. 8. fig. a. I must here call the reader’s attention to the 
extreme beauty of the plates (by G. H. Ford) both in that work and in Dr. Gray’s paper referred to on the 
next page. 
VOL. XI.—Part 1x. No. 1.—October, 1883. 27 
