F. J. Meggitt 
405 
scolex was 0-17 mm. long x 0-14-0-22 mm. wide (Clerc, 0-2 mm.). The 
rostellum measured in length 0-185 mm., in width 0-085 mm., and the 
suckers were 0-075 mm. in diameter. 
The excretory system consists of the usual four longitudinal vessels 
with their transverse commissures. In the scolex they are connected 
by two circular commissures, one encircling the posterior end of the 
rostellum, the other its anterior end. Between these commissures run 
several connecting vessels. 
The genital organs correspond to the usual type. The irregularly 
alternating genital pore lies at the anterior quarter of the segment, a 
little dorsal of the extreme lateral border. The cirrus-sac extends just 
past the longitudinal excretory vessels and has an unusually distinct 
inner layer of nucleated cells. It contains a straight slender cirrus, 
thickly studded with small spines, and at its inner end a few coils of the 
vas deferens. As usual the vas deferens outside the cirrus-sac coils 
excessively before proceeding posteriorly to the testes. These latter lie 
posterior to the ovary and posterior and slightly on each side of the 
yolk-gland. They form an irregular double layer midway between the 
dorsal and ventral surfaces of the proglottis. 
The vagina has a small lumen and thick walls: the gland cells sur¬ 
rounding it are unusually large and distinct. The receptaculum 
seminis is spherical, situated midway between the dorsal and ventral 
surfaces, and in the anterior fourth of the proglottis. It communicates 
with the vagina by an exceedingly narrow passage. 
Hymenolepis interruptus Clerc. (Plate XX.) 
In dissecting a number of sparrows ( Passer domesticus Linn.), I 
found in some large tapeworms belonging to the species Hymenolepis 
interruptus Clerc ( 2 ). The type species was collected from Muscicapa 
atricapilla, so that I believe this to be the first record of its occurrence 
from the sparrow. The worms are 35-40 mm. long (Clerc, 30 mm.) 
and 0-57 mm. wide (Clerc, 0-5 mm.). The scolex (Clerc, 0-45 mm.) 
measures 0-166 mm. long x 0-18 mm. wide. The suckers (Clerc, 
0-25 mm.) are 0-119 mm. long x 0-091 mm. wide, and the rostellum 
(Clerc, 0-02 mm.) 0-128 mm. long x 0-06 mm. wide. The ten rostellar 
hooks are arranged in a single row and are 0-0247 mm. long (Clerc, 
0-02 mm.). In general shape they agree with those figured by Clerc, 
but detailed measurements show that they differ slightly in proportions. 
There is a small neck present, equal in width to the scolex and not 
sharply distinguished from it, its length varying considerably according 
