IVIr. J. N. Ilalhort on Irish [fijdrachiiida. 7 



tcctli ])l:icod close to the inner side of tlie segment ; 5 is 

 iioaily as broad at base as the distal margin ot" 4, ta])ering 

 gradually into a long sharp point; tlie upper and lower surfaces 

 are each armed with a long hair and a sharp spine ; on the 

 outer side close to the base is another spine. 



First pair of Ie</s (length about 814 fi) modified, without 

 swimming-cilia, slightly longer than the body, the segments 

 gradually increasing in length from 1 to 5. Segment 1 very 

 short, 2 and 3 straight, with a number of long bristles; 4 

 curved, with the ventral distal margin notched ; 5 straight 

 (length 2G0 fi), broader than preceding segments, and nar- 

 rowing towards the distal extremity, on which are seven or 

 eight long hairs. Segment 6 (fig. 3) articulates with a 

 conical projection on the penultimate segment, short, with 

 convex sides, very deeply hollowed out on its upper distal 

 margin ; a powerful claw-like structure with a broad shank 

 and sharply bent bifid extremity articulates with the inner 

 part of the excavation ; a few long hairs and a peculiar cone- 

 shaped membrane project from the extremity of the segment. 

 The last three pairs of legs do not present any remarkable 

 characters ; they increase in length from before backwards 

 and are provided with long swimming-cilia ; the terminal 

 segments are armed with two recurved tridentate claws 

 resembling those of Brachypoda. 



During life the colour was a pale yellowish green, marked 

 on the dorsal surface with reddish brown ; Malpighian area 

 yellow, indicated anteriorly by four lobes arranged across the 

 body, 



}[easurenients. 



Length of body 7t)8 



Breadth of body 691 



Length of palp about 270 



Length of leg i 814 



1 -ength of leg ii 704 



Length of leg iii 792 



Length of leg iv 858 



Locality. — Two fully developed examples of this species 

 were found amongst a thick growth of Callitriclie in Loos- 

 caunagh Lough, about ten miles from Killarney, j\Iay 1905. 

 From the peculiar moditication of the first pair of legs there 

 is no doubt that the specimens are males. 



The type specimens are in the Dublin Natural History 

 Museum (register no. 179, 1806). 



