336             Gasterostomatous Parasites of Indian Food-Fishes

body and the relative positions of the gonads of the known species of the
genus Prosorhynchus, from which the identity of the two genera will be clear :—

Species

Shape of body

Position of testes

Position

of
ovary

P. crucibulus Rud., 1819 . .

Cylindrical .

Tandem or obliquely

tandem.

Lateral or

median.

(Syn. G. armatum Molin, 1859,

Bucephalus crux Levinsen,

1881.

P. squamatus Odhner, 1905) .

P. aculealus Odhner, 1905 .

Oval . .

One on either side
of body.

Lateral.

G. sp. Linton, 1910 (Fig. 52) .

Cylindrical .

Tandem . .

Lateral.

P. triglae Nicoll, 1914 . .

Elongated oval

Obliquely tandem .

Do.

P. grandis Lebour, 1908 . .

Oval . .

Nearly tandem .

Do.

P. uniporus Ozaki, 1924 . .

Oval . .

One on either side
of body.

Do.

P.facilis Ozaki. 1924 . .

Cylindrical .

Tandem . .

Do.

P. Ozakii Manter, 1934 . .

Elongated .

One on either side of
body.

Do.

P. platycephali Yamaguti, 1934.

Cylindrical .

Tandem

Do.

P. truncatum Verma, 1936 .

Cylindrical .

Tandem

Do.

In the shape of its body and the tandem position of its testes the new
species, P. manteri, resembles P. crucibulus, Gasterostomum sp. [Linton, 1910,
figure 52], P. facilis, P. platyeephali and P. truncatus, but it can be readily
distinguished from the above five species by its internal organisation. It differs
from P. crucibulus in the more cephalad position of its pharynx and intestine,
the disposition of vitellaria, the anterior extent of the cirrus sac which is over-
lapped partially by the posterior testis, the position of gonads in relation to
the intestine and the absence of filaments in the eggs. From Gasterostomum
sp. Linton, 1910, it can be distinguished by the position of pharynx, intestine,
vitellaria and genital pore and the extent of uterus and cirrus sac. In the
position of pharynx and intestine, disposition of vitellaria and the anterior
extent of uterus and cirrus sac, it can be easily distinguished from P. facilis
and P. platycephali. The new species differs from P. truncatum in most of
its characters such as the topography of the gonads, position of the pharynx,
intestine, genital pore and vitellaria.

PROSORHYNCHUS ARABIANA, n. sp.

Host— Synaptura orientalis Bloch.
Habitat—Intestine.
Locality—Karachi, Arabian Sea.