. The Encyclopaedia Britannica; ... A dictionary of arts, sciences and general literature . s found encapsuled in amonkey, one in the comnvon seal, others in reptiles and sieboldi (fig. 3, B) occurs in tlio body-cavity of anOligochsetous worm {Tubifex rivulorum); it is about 3 mm. long,and consists of au val body (tcolex). to which is attached a cylin-drical tail (proscolex), bearing at the posterior extremity threeairs of hooks; both these parts are capable of motion. The scolexas eight longitudinal excretory canals, and a terminal vesicle;the situated genital
. The Encyclopaedia Britannica; ... A dictionary of arts, sciences and general literature . s found encapsuled in amonkey, one in the comnvon seal, others in reptiles and sieboldi (fig. 3, B) occurs in tlio body-cavity of anOligochsetous worm {Tubifex rivulorum); it is about 3 mm. long,and consists of au val body (tcolex). to which is attached a cylin-drical tail (proscolex), bearing at the posterior extremity threeairs of hooks; both these parts are capable of motion. The scolexas eight longitudinal excretory canals, and a terminal vesicle;the situated genital aperture is the common exit of thevas deferens, the vagina, and a uterus separate from the latter;the development is direct, and it attains sexual maturity withouta change of host. Didhiersia, Perrier (34), contains two species,both from the intestines of varanian lizards. Tbo genus ischaracterized by the presence of two large compressed frilledsuckers, separated by a septum and perforated at their proglottides have three genital apertures resembling those ofBothriocephalus. I. — Tetrarhynchua A, General view of the worm ; x 4. B, head showingthe siKkers, prubosctdes, and excretory canals ; X 25. C, portion of a pro-boscis showing the two forms of hooks ; highly magnified. (AU from Plntner.) The genus Tetrarhynchus was, a few years ago, made the subjectof an elaborate memoir by Pintuer (9), who investigated T longi-collis, V. Ben. The head, in which its most striking anatomicalI>cculiarities are situated, really includes both the head and neckof previous authors (fig. 5, A); it is some 994 mm. long, but only075 mm. in diameter, and bears at its anterior end two obliquelyplaced oval disks (fig. 5, B), each of which is perforated towards theaj>cx by two round holes through which the four proboscides pro-trude. Each of these disks, moreover, shows traces of a divisioninto two, a fact which indicates that it is formed by the fusion oftwo suckers correspondi
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