20 BULLETIN OF THE 
left at the cloaca showed one of the ducts greatly distended, possibly 
with young that had hatched within it. Only one of the tubes had 
been in use. In Fig. 2, Plate XIX., the oviduct that had not been 
expanded is shown at one side (ov), the other having been slit open with 
the cloaca to show internal arrangement. 
The Nidamental Gland. 
Plate XX. Fig. C. 
The gland consists, in appearance, of two thick plates of laminated 
structure. The plates are longer and thicker in the middle, and 
shorter and thinner at each side. The short sides have been applied 
and united ; this leaves an acute point descending from the thicker por- 
tion on the inside of the tube. The insides of the walls are crossed by 
minute strie, between the laminz, which appear transverse, but in 
reality are spiral and ultimately — following the outlines of the anterior 
or posterior borders— terminate, forward or backward, in the longitu- 
dinal folds of the tube itself. The inner edges of the lamine are set 
with minute pores. Near the middle of its length there is a deeper 
transverse groove. This is crossed by the lamine without change in 
their directions on its account. The plates are not distinct from each 
other through the whole of their length; branches frequently cross 
obliquely from one to the other. The bottoms of the grooves between 
them have closely-set transverse partitions. The walls of the gland 
are thicker anteriorly; they begin abruptly, or even extend a little in 
front of their points of attachment to the tube. The appearance is 
such as would result from twisting the inside walls of the duct very 
closely for a short distance. In this we have a hint as to the origin of 
the gland. The distended condition of the oviduct is the only reason 
for supposing the eggs to be hatched before extrusion, after the shells 
have been supplied. 
The Intestines. 
Plate XIX. Figs. 2, 3. 
What remnants of the intestines were left show that the shark pos- 
sesses a spiral valve in the intestine and a cecal pouch behind the valve. 
The intestine (int) opens into the cloaca (cl) behind the openings of the 
oviducts. The ureters unite before reaching the cloaca, into which they 
empty by a single aperture (wa), Plates XH. and XIX. In this speci- 
