H. D. SRIVASTAVA 167
composed of seven to nine grape-like bunches of small follicles. The bunches
are arranged behind one another and open through small ducts into the an-
terior and posterior longitudinal ducts of each side which meet to form the
horizontal vitelline ducts. The latter open into a small, triangular yolk re-
servoir lying just behind the Mehlis gland. A common vitelline duct given
off from the yolk reservoir opens into the oviduct near the opening of the re-
ceptaculum seminis. The intricately coiled uterus lies usually in the inter-
caecal space between the mass of testes and the level of the anterior end of
the vitellaria. Often the uterine coils overlap the caeca laterally and extend
to short distances on the sides of the testicular mass. Terminally the uterus
continues into a feebly muscular and narrow metraterm which lies to the right
side of the pars prostatica. The small ductus hermaphroditicus formed by
the union of the metraterm and the ductus ejaculatorius opens into the ventro-
genital sinus just in front of the acetabulum. The eggs are numerous and
operculate and measure 0.03—0.038 × 0.013—0.015 in size.
Polyorchitrema piscicola is assigned to the family Heterophyidae on ac-
count of the absence of the cirrus sac and cirrus, presence of a large receptacu-
lum seminis, a well-developed gonotyl and a ventro-genital sinus, enclosing
the acetabulum, genital pore and the gonotyl, and Y-shaped excretory bladder.
It, however, does not come under any of the known subfamilies of the family
Heterophyidae and hence a new subfamily—Polyorchitreminae—is suggested
for its reception. In its affinity the new subfamily stands nearest to Sipho-
derinae Manter [1934]. Linton in 1910 created the genus Siphodera for Monos-
tomum vinaldwardsii Linton [1899] and a new family Siphoderidae. In
1934, Manter described a new genus, Siphoderina a form closely allied to
Siphodera, and reduced the family Siphoderidae to the rank of a subfamily,
Siphoderinae, under the family Heterophyidae.
The new subfamily somewhat resembles Siphoderinae Manter [1934]
in the shape of the body, digestive system, position and character of the aceta-
bulum, Y-shaped excretory bladder with long cornua and the piscine host.
It differs remarkably from the American subfamily in the much larger size
of body, absence of cuticular scales or spines, presence of a definite gonotyl,
size ratio of suckers, position and number of testes, position and character of
ovary and the extent of the vitellaria and uterus, besides marked differences in
the measurements of the various structures. The Indian form is found in
fresh-water fish while the two genera of the subfamily Siphoderinae are
parasitic in the intestine of marine fishes.
The following diagnosis is intended both for the genus Polyorchitrema
and the subfamily Polyorchitreminae :—
Body fairly large-sized, muscular, smooth, subcylindrical with broadly
rounded ends. Oral sucker subterminal, muscular, smaller than feebly mus-
cular acetabulum ; the latter enclosed in ventro-genital sinus situated at the
end of the first quarter of body length. Well-developed gland cells present
in the pre-acetabular region. Prepharynx and oesophagus extremely small;
pharynx well-developed and muscular ; caeca broad, lateral, straight, ending