46 2 Proceedings of the Royal Irish Academy. 



trouble they have taken in this matter, and especially to Mr. Kane, who has 

 rendered invaluable help in many ways in the preparation of this paper. 



As regards the methods of collection employed, it may be mentioned that, 

 in addition to the gatherings made with various kinds of nets, some attention 

 was given to washing wet mosses from bogs, mountain torrents, &c, and by 

 this means a few species were obtained which were not found in any other 

 way. A certain amount of bottom material was also passed through fine 

 sieves ; but it was not found possible to employ this method as frequently as 

 could have been wished. Generally speaking, the collections were obtained 

 from quite small pieces of water, such as bog-pools, peat-cuttings, ponds, and 

 small lakes. The only lakes of any size investigated were Castlebar Lough, 

 Islandeady Lough, and Doo Lough ; and it is much to be regretted that no 

 collections could be obtained from the two largest lakes in the district, viz., 

 Loughs Feeagh and Beltra. 



The total number of species now recorded for the district is 90, including 

 three recorded by Brady and Robertson, one found by Mr. Kane, and one 

 given by Canon Norman, but not found again during the progress of the 

 present investigation. The species are distributed among the three Orders as 

 follows : — Cladocera 48, Copepoda 26, and Ostracoda 16. The majority of 

 the species are fairly common types in the British Isles, being either generally 

 distributed or abundant in particular localities. One, however, a species of 

 Copepod from Clare Island, herein described as Camtlwcamptm (Attheyella ?) 

 praegeri appears to be new to science, and there are a few others which may be 

 specially mentioned on account of their rarity in the British records, e.g., 

 Latona setifera, Ceriodaphnia affinis, Alona intermedia (in the British Isles 

 hitherto recorded only from Scotland), Bhynclwt alona falcata, Alonella exigua, 

 and Cyclops rvbcllus. 



The following species are recorded for Ireland for the first time : — 

 Cladocera : — Latona setifera. Alona intermedia 



Ceriodaphnia affinis. Alonella exigua, 



Aeroperus angustatus. 

 Copepoda : — Eurytemora velox. Cyclops affinis. 



Cyclops languidus. Canthocamptus lucidulus. 



nanus. crassus. 



vernalis. pygmaeus. 



bisetosus. zschokkei. 



bicolor. praegeri n.sp. 



rubellus. hirticornis. 



varicans. Nitoera spinipes. 



Ostracoda : — Cypris obliqua ? 



