No. 1629. A NEW RABBIT CHSTODE—HALL. 695 
which respect this form differs from the diagnosis or figures of the 
other species of the group, in which it is given or figured as median 
or in C. pectinata as posterior also. However, in Stiles’s specimens 
of C’. perplexa, which I examined, I find the looastion to be anterior 
as well as median, and indeed it is so figured, though the diagnosis 
(Stiles, 1896) only gives the median location. In C. mosaica the cir- 
rus pouch runs straight practically to the tip, or else curves slightly 
forward, whereas in the available European specimens of C. pecti- 
nata, including Riehm’s cotype and those in the collection of Stiles, 
the cirrus pouch very commonly presents a wide arch, bowing back 
to the posterior part of the segment margin. This is not so noticeable 
in the American specimens of this species from Lyman’s collection. 
The anlagen of the ovaries quite generally appear bilobed in 
frontal section and mature ovaries very often appear so in section, 
though there are branches running anteriorly also. The eontieall 
an 
1/10 mm 
Hie. 4.—CROSS SECTION NEAR MARGIN OF SEGMENT. C, CIRRUS; cp, CIRRUS POUCH; dn, 
DORSAL NERVE; ec, HWXTERNAL EXCRETORY CANAL; ic, INTERNAL EXCRETORY CANAL; Im, 
LONGITUDINAL MUSCLES; mn, MAIN NERVE; 0, OVARY; 7s, RECEPTACULUM SEMINIS; 
Sg, SHELL GLAND; ¢t, TESTHS ; tlm, TANGENTIAL LONGITUDINAL MUSCLES ; tm, TRANSVERSE 
MUSCLES ; wu, mmm « Uv, VAGINA; Ud, VAS DEFERENS ; mM, VENTRAL NERVE; VS, VESICULA 
SEMINALIS; yg, YOLK GLAND 
portion of the ovary is not located anterior of the lobes of the ovary 
as Lyman has described and figured for C. pectinata, but is located 
ventrally, its relation to the lobes being shown in cross-section and 
not in frontal section. Instead of “ Indian-club shaped ” lobes with 
a maximum diameter of 16 » at their tips, as Lyman (1902) describes 
for his specimens of (. pectinata, C. mosaica has a more irregular 
set of lobes with diameters ranging from 40 to 75 p. 
The vitellarium is a densely staining, kidney-shaped gland pos- 
terior and dorsal of the median part of the ovary and between the 
posterior parts of the ovarian lobes. The shell gland is a globular 
structure lying between the vitellarium and the median region of the 
ovary, and is composed of elongate cells. Measuring across the 
proglottid, the lateral dimensions of the various female glands are 
as follows: Width of ovary, 590 to 645 m3 of oe -gland, 200 to 
230 pw; of shell gland, 74 to 92 up. 
