body ('45 mm. from thè anterior end). It has usually thè torni of a transverse 
slit, rendered rather prominent by a muscular rim. The pharynx is compara- 
tively large, having a diameter of • 13 mm. The thin-walled intestine is usually 
situated in front of thè pharynx but may lie entirely dorsal to it. It is of no 
great size. The simple éxcretory vesicle reaehes forward to within a short di- 
stance of thè pharynx. 
The genital glands lie along thè right side of thè body, thè ovarj 7 being in 
front. The testes are almost invariably tandem and contiguous or overlapping. 
The anterior testis is a little external and ventral to thè other. They are of 
ovoid shape, thè long axis 
being oblique, and they are 
situated just behind thè le- 
vel of thè pharynx. In size 
they do not exceed • 11 mm 
The ovary is somewhat lar- 
ger and its axis, although 
slightly oblique, is more in 
thè long axis of thè body. 
It is situated on thè level 
of thè anterior border of 
thè pharynx. The positions 
of thè ovary and testes re¬ 
lative to thè pharynx are not 
invariable for thè lattei' it- 
self is not Constant in posi- 
tion; it varies to a conside- 
rable extent with thè state 
of contraetion of thè ani¬ 
mai. The yolk-glands con- 
sist of two symmetrically 
situated masses, eacli com- 
prising about ten or a dozen 
fairly large follicles. They 
are placed on thè leve! of 
Gasterostomum tergestinum Stossicb. — Ventral view ; somewhat flattened. 'il r ,i 
x 100. — D. St. Yolk-glands ; Ex. Éxcretory vesicle ; ./. Intestine; K. St. ovary; tlie anterior DOlder OI tne 
P.G. Genital aperture; P. Pr. Pars prostatica; 7\ , T 2 . Testes.; V. S. Vesi- pharynx and dose to it, SO 
cala seminalis. , , 
that they are removed some 
distance from tlie margin of thè body. The follicles in each group are arran- 
ged in thè form of a fiat rosette and they lie immediately under thè dorsal surface 
of thè body. The right gland is therefore dorsal to thè ovary and intestine. From 
thè middle of thè left gland a yolk duct runs backwards for a short distance 
then, bending inwards, crosses thè pharynx to meet thè corresponding duct on 
tlie other side. No distinct yolk reservoir is formed at tlie junction. The common 
duct runs outwards and forwards towards thè ovaiy. 
