312 Cestode of Hedgehog 
posteriorly to the centre of the proglottis, half-way between dorsal and ventral 
surfaces. It is bilobed, the lobes being directed anteriorly. The vitelline duct 
arises from the common posterior basal portion and runs anteriorly, at first 
on the ventral surface, later crossing the segment to open in the centre into 
the oviduct. 
At its first appearance the uterus is an amorphous sac situated anteriorly 
and, in a transverse section through that region, occupying the whole of the 
proglottis. As it develops it extends posteriorly and sends out numbers of 
branches which ramify in all directions. This process continues, the whole 
uterus resolving itself into a meshwork of tubes; these ultimately form capsules 
containing at first several, but later only a single egg. 
Key to Species of Oochoristica. 
. 0. megastoma (Dies.) 
... ... • •• ( 2 ) 
.(3) 
1. Egg-capsules contain several eggs. 
Egg-capsules contain only one egg ... 
2. Testes extend anteriorly to ovary. 
Testes posterior, or lateral and posterior to ovary 
3. Host, Amphisbaena alba 
Host, Zonurus tropidosternum 
4. Vagina opens anteriorly to cirrus. 
Vagina opens posteriorly to cirrus. 
5. Genital ducts pass between longitudinal excretory vessels 0. tetragonocephala (Brem.) 
Genital ducts pass dorsally to longitudinal excretory vessels 0. didelphydis (Rud.) 
(4) 
0. amphisbaena (Rud.) 
0. zonuri Bayliss 
(5) 
( 6 ) 
6. Testes lateral and posterior to ovary 
Testes posterior to ovary 
7. Rostellum absent 
Rostellum present 
8. Testes 50 
Testes 100 or more 
9. Cirrus-sac not reaching outer longitudinal excretory vessel 
Cirrus-sac reaching or passing outer longitudinal excretory 
vessel... 
10. Genital ducts pass between longitudinal excretory vessels 
Genital ducts pass dorsally to longitudinal excretory vessels 
11. Eggs absent from centre of proglottis 
Eggs present in centre of proglottis... 
12. Testes 15-20. 
Testes 20-30 ... 
Testes over 30 ... 
13. Receptaculum seminis present 
Receptaculum seminis absent 
14. Testes 39-46 ... 
Testes 70-80 ... 
15. Eight longitudinal excretory vessels 
Four „ >> 
(, Oochoristica pseudopodia (Krabbe), O. w (Rud.), and O. spl von Janicki 1906, are not 
included in the above key, their anatomy not having been sufficiently im estigated.) 
REFERENCES. 
Beddard, F. E. (1914). On two new species belonging to the genera Oochoristica and 
Linstowia. Proc. Zool. Soc., 269-280. ,. , 
Cohn, L. (1903). Helminthologische Mittheilungen. Arch. f. Naturgeschichte, 69, 48 68. 
(7) 
( 11 ) 
O. cryptobothrium (v. Linstow) 
( 8 ) 
O. incisa Marotel 
(9) 
O. marmosae Bedd. 
( 10 ) 
O. rostellata Zsch. 
O. surinamensis Cohn 
O. bivittata v. Jan. 
( 12 ) 
O. tuberculata (Krabbe) 
O. truncata (Rud.) 
(13) 
(14) 
(15) 
O. agamae Bayliss 
O. wagneri v. Jan. 
O. sp Beddard 
O. erinacei n. sp. 
