124 MR. F. J. MEGGITT ON A 
going to the posterior margin of the proglottis, where it is joined 
by the vagina, and then, bending at an angle of 30°, it runs 
anteriorly to open into the obtype just under the odclapt. Its 
wall consists of an outer epithelium, a muscular layer, and a 
thick layer of ciliated cubical epithelium, the wall being 
‘0034 mm. in thickness, surrounding a lumen ‘009 mm. dia. 
At its opening into the ooty pe the lumen of the oviduct 
decreases to ‘003 mm. dia. 
Benedict states that gland-cells are scattered along the external 
epithelium, but I have been unable to see them. 
The odtype (Pl. I. fig. 11) is a rounded body, 014 mm. dia., 
with walls ‘0029 mm. thick, composed of an inner non-ciliated 
epithelium, a circular machen layer, and an outer epithelium ; 
round it are scattered nuclei, ‘0011 mm. dia., not arranged in 
definite rows as Kraemer states. Surrounding the odtype and 
opening into it by fine ducts are shell-glands of irregular shape 
and with definite nuclei. Benedict represents the odtype as 
an elongated tube between the opening of the common vitelline 
duct and the uterus: in the position mentioned there is certainly 
a duct which appears, as he says, like a specialised portion of 
the oviduct, but this is not the odtype. 
The vitellaria consist of small follicles scattered along the 
whole length of the lateral margins of the proglottis. The 
follicles are ‘0092 x 0069 mm. in transverse section, with a 
distinct nucleus, (0034 mm. dia., and are grouped together in 
fours or fives, each group being enclosed in a membranous sac 
‘08 mm. dia. Two longitudinal ducts, one on each side, run 
down the proglottis, receiving numerous fine ducts from the sacs, 
to its hinder end, where they turn inward and join to form a 
common duct. This duct runs longitudinally for a short distance 
to open into the odtype. It has a lumen -0029 mm. dia., with 
walls ‘0023 mm. thick, consisting of inner and outer epithelia 
surrounding a well-developed circular muscular coat : connective 
tissue nuclei form a definite layer round it. 
The uterus passes as a narrow tube from the odtype under the 
connecting portion of the ovaries, and expands as a large sheet 
with 6-10 lateral outgrowths along the ventral surface of the 
proglottis (Pl. I. fig. 8). In older segments, the uterus fills 
the entire segment to the exclusion of all other organs. The 
ova escape through a cleft in the mid-ventral line. 
Lirr- History. 
Historical. 
The life-history of this species is unknown. Von Siebold (24) 
states ‘‘le Zenia longicoltis et le ZL. ocellata qu'on rencontre 
enkystés, hors du canal intestinal, dans la foie de divers 
Salmones et Perciides:” the fish are swallowed ly pike or 
perch, in the intestine of which the parasite becomes adut. In 
