HELMINTHOLOGY-HELMINTHES TREMATODES. 473

pore transversim elliptico, subdepresso; acetabulo ori oppo-sito,” which he found attached by the acetabulum to thesoft inferior surface of the abdomen of Carcinus mcenas.For the rest, Eathke does not believe that these animals areproperly placed, with the Trematoda ; as he has foundminute Amphipoda in their stomach, they do not conse-quently draw their nourishment from the animals theyinhabit.

According to Bellingham (Annals Nat. Hist, xiv, 1844,p. 162), Pentastomum [ Pentastoma ] tcenioides occurs also inIreland .

Schomburg (Froriep’s n. Not. Nr. 647, p. 136) has dis-covered a trematode entozoon in the Leech , and named itHeptastomum Mrudinum.

Valentin (Valentines Repert. Bd. viii, p. 90) in examining,in the month of August, thin sections of Frog’s kidneysunder the compressorium, observed embryonic entozoa fur-nished with a crown of cilia, such as also occur in theurinary bladder of Frogs , as well as a larger Trematode withan obvious acetabulum.

According to Henle’s observation (Zeitschrift fur rationelleMedizin. 1. c. Bd. iii, p. 6), ciliary motions are evident inmany places in the lateral vessels of Cercaria echinata, theanterior part of the bodies of which animals he observed tobe beset with minute spines. He also remarked in manyinstances, in this Cercaria, larger and smaller spherical cor-puscles, resembling the so-termed vitreous corpuscles ofthe Cyst-worms, which frequently presented concentric striae,and exhibited, as it were, a central opaque nucleus, and brokeunder pressure. The Reporter is also acquainted withsimilar corpuscles in several other Cercariae; they are con-tained in the excretory organs of these trematode-larvae, andin Histrionella ephemera have been regarded by Ehrenberg(Symbolae physicae) as ova.