87 
The studied was that of the hexaeanth embryo, as found 
encysted 24. 8<>. or 5o liours after ingestion (hgs. 4t>-4l>. 52. 58). gen- 
erally oval, or at times llask sha])ed — that is. with a body and a tail. 
Ther(‘ may be evident at this time a rather ample primary cavity 
which in a tiask-shaped embryo is in relation with tin' post(‘rior part 
Figs. 52, . '>3. — Hexucanth embryos of IL. without cavity, eoiitaiiiiiiif calcareous corpuscles. 
Enlarged. (After GrasU A Rovelli. 1892a. jd. 3. figs. 10. 11. respectively.) 
Fig. .51.— Embryo of II. vann after the appearance of the primordia of rostellum and suckers; 
u<"., suckers; pr.mr.. j>rimary cavity; rox.. rostellum. Enlarged. > .\fter Grassi A; Rovelli. 1892a, 
])1. 3, tig. 12.) 
Fig. 55. — Longitudinal section of embryo of ][. naiiu: j,r. car.. ]irimary cavity. Eidarg(‘d. Alter 
Gra.ssi & Rovelli. 1892a. x>l. 3, tig. 14.) 
Fig. 5(1. — Longitudinal and slightly obliituc section of embryo of H. aaiai after the appearance of pri- 
mordia of rostellum and .stickers; ac.. sucker; r(i.<.. rostellum; pr. car., ju-imary cavity. Enlarged. 
(After Grass! Rovelli, 1892a. pi. 3. fig. 15.) 
Fit;. 57. — Embryo of II. nann. Same stage as x'receding figure, in cross-scction; uc.. sucker; /o.v.. ros- 
tellum. Enlarged. (After Grass! A Rovelli, 1892a. pi. 3. fig. Id. i 
Fig. .58. — Cercocystis of H. nana completely developed. Enlarged. After Grass! w Rovelli. 18u2a. 
pl. 3. fig. 13.) 
of the i)ody, and sometimes with the tail also (tigs. 5n. 51). The 
embryonal hooks are generally found on tlie tail, sometinu's also on 
the posterior part of the liody. arranged in pairs. The embryos often 
show irregularities in form, prominences, etc. (tigs. 47-40. 58). In 
the middle of the body there may be found one. two. or three calcare- 
