A NEW MAMMALIAN CESTODE. 1055 
The following characters will define the new genus, and the 
name will suggest its affinity with the Acoleide :— 
MONGCOCESTUS, gen. nov. 
Scolex unarmed; proglottids not longer than broad. Genital 
pores regularly alternating. Water-vascular tubes two pairs lying 
side by side, connected by transverse vessel from inner tubes in each 
proglottid; no network. Longitudinal muscles feebly developed, 
without bundles. Generative organs visible in first or second pro- 
glottid ; first genital pore in segment 6. Testes numerous im 
transverse rows posteriorly, within area bownded by water-vessels ; 
sperm-duct at first very wide and covered by glandular cells, after 
this short and narrow, without coil or vesicula seminalis; cirrus- 
sac large and very muscular, cirrus unarmed. Ovary curved in 
front of smaller vitelline gland. Vagina present in a few early 
segments, later aborted, with exception of spherical receptaculum 
seminis. Uterus retiform, meshwork later tending to confluence. 
Eggs with delicate shell. 
For the present the above definition will have also to serve 
for the new species, which I call MWonecocestus erethizontis, sp. n. 
