C4 V. VAVRA OX THE PHYLLOPODS LIMNADIA LENTICULARIS (l.) 



As may be seen from the foregoing list of synonyms, this species 

 was described as Monoculu-s lenticularis by Linne. His specimens 

 came from Finland, and it was only because the species had not 

 been found again in that country up to 1871 that Lilljeborg had 

 doubts as to the propriety of retaining the name given to it by 

 Linne. In 1875, however, Sahlberg found it again in Finland, 

 and in 1877 Lilljeborg placed the identity of M. lenticularis (L.) 

 with J), gig as Herm. and L. hermanni Brong. beyond all doubt. 



Some examples of this interesting Phyllopod were received by 

 me in June 1899 from my friend Professor F. Klapalek, and 

 immediately afterwards I visited the "spot, near Wittingau, in the 

 south of Bohemia, where they had been found. They occurred 

 in a quite shallow pond harbouring a rich aquatic vegetation, 

 and I was able to collect numerous specimens and thus have 

 the opportunity of watching the living animals. They swim 

 upon their backs exactly in the manner of Branchipus, a fact 

 about which some doubt has been expressed in recent times. 

 When at rest the animals lie upon their sides. The bivalved 

 shell is about 15 mm. long, 10 mm. high, and, seen from above, 

 very narrow, only being about 4 mm. broad. It is highly 

 polished and transparent, with seven or eight concentric lines 

 marking stages in its growth (Figs. «, c). 



The body of the animal does not fill the whole of the shell. 

 The rounded head is bent downwards, and is furnished with a pair 

 of large eyes, together with an eye-spot. The swimming antennae 

 are pretty long and powerful, the shorter dorsal branch being 

 usually ten-jointed, and the longer ventral branch eight to 

 twelve-jointed, both being armed with long swimming bristles. 

 On the back of the animal there is a so-called organ of attachment 

 (Haftorgan). There are twenty-three to twenty-four body- 

 segments, and the same number of pairs of feet, of which the 

 first ten are equal in length, while the remaining pairs become 

 gradually shorter. With the exception of the last, the feet 

 carry two branchial appendages. 



The ninth, tenth, and eleventh pairs of feet are provided with 

 long thread-like processes (cirri), with which the eggs are held in 

 position on the back (see F'ig. c). The powerful post-abdomen or 

 tail (Fig. d) is toothed on the dorsal edge, and furnished with two 

 plumose bristles. At the end of the tail are two large movable 

 claws, having little spines along their hinder edges. 



