666 Proceedings of the Royal Irish Academy. 



for example, the Kotifer identified by her as Furcularia micropus (?), 

 Gosse, seems, apart from other differences, to have been more than 

 twice the size of Gosse's species. Making some allowance for dupli- 

 cation in the case of such forms as the above, the whole known Rotifer- 

 fauna of Ireland now reaches a total of about 275 species. 



Por several of the drawings annexed to this Paper, and for a 

 knowledge of certain of the points of structure illustrated by them, 

 I am much indebted to my valued correspondents, Mr. C. E,. Eousselet 

 and Mr. F. E. Dixon-Nuttall. Such species as are described and 

 figured in Hudson and Gosse's Monograph of the Eotifera, vols, i., ii., 

 are cited here without bibliographical references, such references 

 being given only for species described in the supplement to that work 

 or in more recent separate Papers. 



Order I.— EHIZOTA. 



Family I. — Floscitlaeiid^. 



Floscularia regalis, Hudson. A number of examples of this easily- 

 recognised, seven-lobed, species occurred on Sphagnum and on 

 Utricularia in a bog-pool two miles S.E. of "Westport, and in 

 a swamp near Castlebar ; 1889-92. 



F. coronetta, Cubitt. {F. tenuilolata, Anderson, Journ. Asiat. Soc. 

 Bengal, 1891). Six specimens of this rare species were found 

 by me on Eanunculus in a small lake in the Knappagh district, 

 two miles from "Westport, 1891. A few more occurred on Chara 

 in a bog-pool 2|-m. S.E. of "Westport in 1894. 



F. ornata, Ehrenberg. Fairly common on Utricularia, Chara and 

 Myriophyllum in marshes and lakes. Castlebar and Knappagh, 

 1889, '91, '92, '94. 



F. cornuta, Dobie. Frequent in marshes and bog-pools on Chara and 

 Utricularia, in different places round "Westport and Castlebar ; 

 1889, '91, '92, '94. 



F. Cyclops, Cubitt. Scarce ; eight examples occurred on Chara in a 

 lake in the Knappagh district, 1891. 



F. ambigua, Hudson. This species, first discovered by me on Tent's 

 Muir, Fife, in 1881, is fairly numerous in the bog-pools all 

 round "Westport. 



