■686 Proceedings of the Royal Irish Academy. 



elongated than in P. collinsii : and tlie dorsal plate of the lorica 

 bears eight spines only in the latter species, but twelve in the 

 former. It is clear, as has already been pointed out by more 

 recent writers, especially by Ternetz, that those two species 

 deserve to be associated together, and removed from the 

 genus Dinocharis. Both species are rare, but widely dis- 

 tributed. Mr. "Western has obtained both in England, as I 

 have also done in Scotland ; and both have been also taken 

 by German and American observers. A few examples of P. 

 suiquadratus occurred in a lake near "Westport in 1894. 



Scaridium longicaudum, Ehrenb. A few examples of this species 

 occurred in sediment from the lake at Castlebar, 1891. 



S. eudactyht'um, Gosse. I found a few examples of this handsome 

 species in sediment fi'om the lake at Castlebar in 1891 : this is a 

 rare species. I made a second visit to the lake, expecting to find 

 more of this beautifully transparent creature, but failed to find 

 it again. It is one of the most tantalizing creatures I have met 

 with ; when one is in the field of view sailing gracefully and 

 slowly through the water, and the observer is enjoying the sight 

 of its symmetrical and crystalline form, then, all of a sudden 

 without the least warning, it springs with lightning speed out of 

 the field of view. This species was discovered by me, in 1881, 

 in Perthshire. 



Stephanoi^s muticus, Ehrenb. I found a number of examples in two 

 small lakes amongst Myriophyllum, and in a marsh-pool, near 

 Westport, 1891, '92. 



8. chlcena, Gosse. I got a number of specimens in marsh-pools near 

 Westport in 1891, '92. I am somewhat doubtful as to its 

 generic relations ; it is very different from any other species, and 

 probably deserves to be removed from the genus Stephanops. 

 .8. tripus, Lord. H. and G., Sappl., p. 36, pi. xxxiii., 24. S. le'ijdigii, 

 Zacharias. In August, 1894, in a small lake in the Knappagh 

 district, I obtained a few specimens, which I refer to this species. 

 They possessed two small red eyes, wide apart ; a dorsal spine 

 as long as the whole animal ; a two-jointed foot, with a small 

 fine spine at the base of the toes. The total length of the 

 animal was xio inch. This description accords with that given 

 by several German observers to a Stephanops described by them 

 under various specific names. I am of opinion that they have 

 all been describing the same species, and that it is identical 



