118 



tares are rather far apart and turned forward in an oblique direction; the skin between 

 them is closely covered with normal hairs of medium length, and this hair-coat extends for- 

 ward as far as to the orifices of the receptacula seminis and backward as far as behind the 

 genital apertures, whereas the peculiar hairs of the trunk are found on nearly all the 

 remainder of the area. The well-developed caudal stylets are situated within the chitinised 

 part, close together a little behind the genital apertures; each of them is provided with two 

 setae, one of which is exceptionally long. 



MALE. Unknown. 



OVISACS. They differ somewhat in size and are more or less oblong; an ovisac of 

 medium size (fig. 5b) is -44mm. long, 36 mm. broad; the eggs are large and not numerous. 



LAEVA and POST-LAEVAL DEVELOPMENT. Unknown. 



HABITAT. In the marsupium of a female of Metopa rubrovitfata G. 0. Sars Avere 

 found one female (with three spermatophores) and four ovisacs. 



II. Sphaeronella paradoxa n. sp. 



(PI. Ill, fig. 4 a— 41; pi. IV, fig. la— 1 h.) 



FEMALE. A very large specimen is T26 mm. in length, the animal represented 

 in fig. 4 a is '92 mm. and that in fig. 4 b only -71 mm. in length. In the older specimens 

 the body is not regularly globular, for its ventral surface shapes itself more or less con- 

 spicuously into a very broad, low cone, near or from the top of which proceeds a short 

 thread by which the animal is fastened in the marsupium of the host; in consequence of 

 this shape the animal does not show its longest dimension in the distance from its small, 

 but well defined, head to or behind the genital area. In order to explain these peculiarities 

 it will be to the purpose to mention the young specimens. A young animal which is breaking 

 out of the skin of the pupa (fig. 1 g) is -207 mm. in length, with an oblong, normal trunk. 

 A somewhat larger specimen, -36 mm. long, is represented in fig. lh; at some distance 

 behind the middle of the ventral surface of the trunk we see a proximally broad, short, 

 conical projection (t), which terminates in a short, pretty thick thread, the end of which is 

 expanded into a small disk (u) and this disk is fastened, e. g. to one of the gills of the host. 

 In the specimen represented the conical part has been flattened and pushed to one side. 

 This attachment continues throughout the life of the animal, and as a rule the thread gets 

 very much twisted (fig. 4 a and fig. 4 b), because the animal turns itself, and at the same 

 time it gradually gets its longest diameter from the base of the thread, or a little behind 

 it, up to the dorsal surface somewhat behind the head, whereas the genital area, the place 

 of which is shown in fig. 4 b by a spermatophore, becomes situated more or less high up 

 on the dorsal surface; in other words: nearly the whole ventral surface forms a much 

 stronger, somewhat conical curve and a much more extensive area than the back, which no 



