Utero-gestation in Trygon Bleekeri, 425 
Elasmobranch fishes, remain as direct channels between the 
pharynx and the external medium, 
There is also noticed a small external yolk-sac about as 
big as a raisin, with a thread-like stalk which perforates the 
body-wall, and, expanding, is attached to the anterior end of 
the spiral gut on the ventral aspect. 
The yolk-sac is empty and is evidently dwindling ; in the 
more advanced foetus of the Mahénadi specimen it had alto- 
gether disappeared. 
On opening the abdomen of the foetus the greatly distended 
spiral gut is seen lying to the right *, and the left lobe of the 
liver to the left *. The stomach is small and empty and is 
pushed up beneath the pectoral arch. 
The small short duodenum, which is guarded at the pylorus 
by a stout valve-like fold, is, like the anterior part of the 
spiral gut, full of coagulated lumps of the uterine secretion. 
The posterior three-fourths of the spiral gut is stuffed with 
viscid, grumous, bile-stained matter. 
The rectum is sharply constricted off from the spiral gut 
and looks like a solid cord ; dorsal to it lies the rectal gland 
in a fold of mesentery common to it and the testes, to which 
last it is intimately adherent. 
The liver is of large size and perfectly colourless; the 
spleen is also large. 
The left testis is several times larger than the right, 
perhaps because the pressure of the distended spiral gut has 
hindered the growth of the latter. 
The external gill-slits are closed ; their anterior edges are 
finely pectinated. 
On laying open the capacious pharynx the wide internal 
orifice of the spiracle is displayed. It lies in the same plane 
with the branchial clefts proper, and symmetrically with them, 
so that its homodynamy with them is of diagrammatic plain- 
ness, and it differs from them chiefly in being widely open, 
while they are closed by the close approximation of the 
branchial bars. 
It only remains further to remark, concerning’ the foetus, 
that while its generic and subgeneric characters are quite 
distinct, it has not yet acquired its full specific characters. 
Except for a large centro-dorsal boss surrounded by a few 
small tubercles its skin is quite smooth; its tail-spine is 
well developed, but entirely sheathed in skin. Its colour is 
much like that of the adult, but lighter, being uniform brown 
dorsally and olive-grey below except along the abdomen. 
* I, e, of the foetus, 
