H. D. SRIVASTAVA                             327

anterior end of the body. The pharynx surrounding the mouth is a fairly
muscular structure measuring 0.1—0.12 in diameter. It is situated in the
median line at the junction of the middle and posterior thirds of the body
length. The oesophagus is a straight, narrow tube of 0.2—0.25 in length.
The intestine is sac-shaped and measures 0.26—0.35 × 0.14—0.2 in size.
It is situated in the median line in level with the anterior testis.

The posterior testis, 0.42—0.6 × 0.24—0.3 in size, lies between the
pharynx and the right body wall, extending from the last quarter of the body
to the level of the hinder margin of the intestine. The anterior testis of
0.24—0.4 × 0.14—0.26 in size lies obliquely in front of the posterior testis,
between the right body wall, posterior half of ovary and the shell gland com-
plex. The cirrus sac is highly developed and measures 0.66—0.9 × 0.2—0.3
in size. It extends forwards up to the level of the anterior end of the
oesophagus and encloses a vesicula seminalis, 0.2 —0.3 × 0.14—0.2, a pars
prostatica surrounded by gland cells, 0.36—0.54 × 0.1—0.15, and a narrow
ductus ejaculatorius, 0.1—0.15 long. The genital tongue extends into the
funnel-shaped genital sinus which opens to the outside on the ventral surface
a little in front of the hinder end.

The ovary is pear-shaped and lies to the right of the median line extending
from the level of the middle of the anterior testis to first quarter of body length.
It measures 0.26 —0.32 × 0.26 —0.3 in size. The oval, compact shell gland
mass lies immediately behind the ovary. A short Laurer's canal is given off
from the oviduct. The vitellaria are composed of large rounded follicles
arranged longitudinally in pairs on the lateral sides of the body, extending from
the level of the middle of ovary to that of the anterior sucker. The uterus
extends forward up to the anterior limit of vitellaria. It contains a large
number of light brown eggs of 0.034—0.036 × 0.011—0.013 in size.

The excretory bladder is as in B. Icarvei Bhalerao, 1937.

Diesing in 1855 created the sub-genus Bucephalopsis for the larval form of
B. haimeanus which subsequently proved to be larva of B. gracilescens (Rud.,
1899). Nicoll [1914] raised the sub-genus to the status of a genus with B.
gracilescens as the type. A number of species have since been described
under the genus, but Eckmann [1932], after a critical study, maintains only
eight species— B. haimeanus Lacaze-Duthiers, 1854 ; B. gracilescens Rudolphi,
1819; B. triglae van Beneden, 1870; B. arcuata Linton, 1900; B. pusilla
Stafford, 1905; B. exilis Nicoll, 1915; B. elongata and B. latus Ozaki, 1928.
The description of B. arcuata and B. triglae being inadequate their validity
has been questioned by Bhalerao [1937]. Verma [1936] described five new
species of the genus— B. fusiformis, B. garuai, B. magnum, B. confusus and
B. minimus from fresh-water fishes of Allahabad. Of these the last three,
in the opinion of Bhalerao [1937], are synonymous with B. garuai. The minor
differences existing between B. garuai and the last three species are ascribed
to either difference in age or to individual peculiarities. Recently
Bhalerao [1937] has described a new species— B. karvei—from the intestine
of Belone cancila from Poona and has given a key to the valid species of the
genus.