622 SKATES’ EGGS AND YOUNG. 
add the explanations to the figures which he has so kindly 
placed at my disposal for this article. 
:# Egg case. — This singular structure has the general form of such parts 
in egg-laying Selachians. The whole case, in the species here described 
is between six and seven inches in length, of a deep greenish-brown 
color, and composed of minute parallel dikileni, which give it a striated 
appearance and a silky lustre. The central pouch (fig. 85, «), for the pro- 
tection of the yelk and the embryo, is about two inches long, an inch and 
a half wide, bulges in the middle, and has a hollow, slender, curved horn 
ee PORE each tor- 
e fore end of the 
eria is deeply concave, 
and thickest, while. the 
hinder is thin, nearly 
square, and ragged; it is 
from this part that the 
embryo escapes, after the 
o 
G 
each other. The hinder 
horns project backwards 
@ as they lie in the oviduct, 
©» of the water which pass- 
es throngh the egg dur- 
ing incubation. 
At the base of each 
fore horn is a slender 

Egg case of Skate, one-half natural size; a ach fi 5 A : ee 
the yelk; bb’, openings for the inward and outward fto fow . Projection or spur (6 
we weaving ba ine lateral PL ro formed by the inter- about half an inch in 
length, the whole outer 
border of which breaks up into a series of silky filaments, and these are 
especially abundant near the free end. Similar filaments are given 
from the whole border of the capsule, and all become tangled and woven 
together in such a manner as to form a broad and somewhat thick mem- 
brane on each side (d). This membrane was found entire only on cases 
taken from the oviduct, and on those newly laid. In all such, however, 
as: have embryos somewhat at it is more or less destroyed, an 
for the most part only tufts of it remain at the base of each horn. The 
