44 4 Proceedings of the Royal Irish Academy. 



found at Achill Sound (D.E.P.B. and EL W. L.), Louisburgh (H.W.L.), 

 Belclare (X. H. I\), and also at Curraun, near Achill Island. 



Porcellio dilatatus Brandt. 



A single specimen of this species was captured in the hotel garden on 

 Clare Island. Elsewhere in Mayo it has been found at Louisburgh (also 

 in a garden) and at Killala. It seems probable that this species is not native 

 in the district, but has been introduced with garden plants. 



Cylisticus convexus (De Geer). 



Outside Clare Island this species has not yet been found in Co. Mayo, and 

 it cannot be regarded as common on the island. A little colony was discovered 

 under stones near the base of the castle at the harbour, and it was also 

 captured in the hotel garden. A collection of woodlice made by various 

 workers on Clare Island contains one specimen of this species, the precise 

 locality not being stated. 



Isopoda Fluviatila. 



Asellus aquaticus Linn. 



The only fresh-water Isopod observed on Clare Island was Asellus 

 aquations, which was obtained in the small lakes of the island, as well as 

 on the mainland. This species is common in ponds, lakes, and streams all over 

 Ireland, and is the only fresh-water Isopod so far detected in this country. 



