1893.] Eggs of Pityophis Melanoleucus. 883 
stance appears to be absent also from the other layers; which 
may be easily teased up, when the fibres float off freely in the 
mounting medium. 
A rough analysis of the shell gives the following results. 
Water 29:5 per cent. 
Soluble mineral matter (almost 
entirely calcium carbonate) ^ 16:6 per cent. 
Organic matter 53°7 per cent. 
99°8 
Well advanced embryos were found within the eggs. These 
must have been at least 10 or 11 weeks old. Those examined 
numbered equally males and females. They have an average 
length of 6? inches, the tail being 1?» inches in a male and 
slightly less in a female specimen. 
The embryos lie deeply embedded on one side of the abun- 
dant yolk, which envelops, and almost completely surrounds 
them, being packed thoroughly in among the folds; and in 
aleoholie specimens, requiring to be largely cut away to 
expose the full length of the embryo. The young snakes are 
arranged in somewhat irregular spiral coils, the larger folds of 
which are directed in the long diameter of the egg. There 
is no regularity in the arrangement of the folds; the spiral 
being sometimes wound in a left-handed, sometimes in a right- 
handed direction, figs. 7 and 8. Large clear albuminous 
masses are frequently embedded in the yolk. 
The umbilical cord is short, measuring about $ inch in 
length and ++ inch in diameter. It leaves the body anywhere 
between ài and 1inch in front of the vent, between which 
points the somatie folds are entirely free from one another, 
while for a distance of an inch to an inch and one-half ante- 
rior to the umbilical cord they are only very feebly united. 
Beyond this point the gastrosteges are complete. These num- 
ber in all 216 in one 9 specimen examined—a number 
slightly less than the adult possesses. The anal plate is single, 
and the number of scales in a vertical row normal. 
On the head the absence of certain plates present in the 
adultis noticeable. The seutes have not yet developed over 
