L. H. Gough 
115 
were contracted to their fullest extent, the strobila being spirally 
twisted, or frilled by the extremity of the contraction. Some of the 
specimens, however, could be relaxed sufficiently before fixing, to 
enable good sections to be made. 
In my specimens the scolex is generally rather smaller than the 
size given by Stiles, being about O'o mm. in diameter instead of 
0'768-0'9 mm. The strobila directly behind the scolex is only one-half 
to two-thirds this width; it begins to widen 2-3 mms. behind the head, 
and attains 1'3 mm. at 1 cm. from the scolex. The widest segments are 
about 2'5 mm. wide, by 0‘07 mm. long, and the thickness varies from 
0‘25 mm., at the level of the ventral canals, to OT mm. along the 
median line. In consequence of the thinness of the median portion 
of the segments, the strobila has a tendency to fold over on itself 
longitudinally. 
There are four to eight testes on either side of the segment, six 
being a common number. These all lie laterally or dorsally to the 
ventral canal, and are arranged in one row, or in two consecutive 
transverse rows of three or four, according to the state of contraction 
of the worm. (Text-figure 1 t.) In Stilesia hepatica Wolff, some of 
the testes are median to the ventral canal. (Text-figure 2 t.) The 
vas deferens of each side starts dorsally to the testes, as in Stilesia 
hepatica Wolff, (v.d.) and crosses above both the ventral canal and 
the dorsal canal; the right and left branches of the vas deferens meet 
in the median field, here they combine and form a common vas 
deferens which runs across the segment towards the pore side, crossing 
the dorsal canal ventrally, and the ventral canal dorsally, just as in 
Stilesia hepatica Wolff, (see figures.) Arrived lateral to the ventral 
canal the vas deferens becomes swollen with spermatozoa, and forms 
many closely wound convolutions, which lie either ventral to the 
testes, or when the worm is well expanded anterior to them. The 
absence of convolutions of the vas deferens can consequently no longer 
be used to differentiate Stilesia glohipunctata (Riv.) from Stilesia 
vittata Railliet. The cirrus pouch in my sections is invariably ventral 
to the vagina. It lies in the anterior corner of the segment, 
alternating irregularly on the right or left of the strobila. When the 
strobila is very contracted, the cirrus pouch and vagina are often 
extruded together so as to form a small knob-like projection covered 
of course by subcuticula and cuticula. 
The ovary (ov,) lies median to the ventral canal and lateral to the 
dorsal canal of the pore side. The oviduct (o.d.) meets the seminal 
8—2 
