320
Gasterostomatous Parasites of Indian Food-Fishes
duct of the right side. The cirrus sac is an elongated, oval structure, measur-
ing 0.3—0.5 × 0.06 - 0.2 in size, and extending anteriorly almost to the level
of the anterior limit of the posterior testis. It encloses a small, ovoid vesicula
seminalis, 0.06—0.14 × 0.04—0.12, a spindle-shaped pars prostatica of
0.16—0.36 × 0.04—0.1 in size, surrounded by prostate glands and a narrow
ductus ejaculatorius of 0.06—0.14 in length. The ductus ejaculatorius has a
cuticular lining and opens into a roughly triangular genital sinus, at the base of
a tongue-like protuberance known as genital tongue, cone or ' Geschlech¬
tszapfen'. The genital sinus is surrounded by numerous gland cells which
open into it and secrete the wall of the spermatophore. The genital pore lies
subterminally on the ventral surface a little in front of the hinder end.
The spherical ovary of 0.1-0.26 in diameter lies at the junction of the
second and posterior thirds of body length close in front of the anterior testis.
It is separated from the latter by the compact shell gland complex and the
vitelline duct of the left side. The shell gland complex lies between the
left body wall, ovary and the anterior testis. A small Laurer's canal is given
off from the oviduct just before the latter receives the common vitelline duct.
The vitelline glands are composed of small, pear-shaped or oval follicles
arranged roughly in pairs along each side of the body. They extend longi-
tudinally from the anterior margin of the ovary to the first third of body
length. In contracted specimens the vitelline follicles become aggregated into
a mass. The initial part of the uterus runs backwards and passing between the
two testes crosses over to the opposite side and continues anteriorly into an
irregular coil up to the first sixth of body length and then turns backwards to
open into the genital sinus. The whole of the uterus is full of light yellow eggs
of 0.023—0.027 x 0.0114 in size. The eggs are oval in shape and have a
small knob at one end.
The straight, tubular, excretory bladder extends from a little in front of
the anterior limits of the vitellaria to the excretory pore which is situated close
to the genital opening.
The genus Bucephalus was created by Baer in 1827 with B. polymorphus
as the type species. Though several species have been described under this
genus, Eckmann [1932] after a careful study accepts only five species as valid,
B. polymorphus Baer, 1827, B. gorgon Linton, 1905, B. sp. Linton, 1910, B.
carangis MacCallum, 1917, and B. elegans Woodhead, 1930. Since the publica-
tion of Eckmann's paper five more species have been added—B. uranoscopi
Yamaguti, 1934, B. mytili Cole, 1935, B. tridentacularia. B. aoria and B.
jagannathai Verma, 1936. In all, nine species of the genus are known, besides
B. mytili which is described from larval form.
In its number of tentacles the new species, B. indicus, resembles B.
jagannathai, but it differs from the latter in most of its characters, such as,
shape of body, shape and character of tentacles, extent of cirrus sac, vitellaria
and uterus and the topography of the gonads, besides differences in measure-
ments. In the nature of its tentacles, topography of gonads, extent of