Clare Island Survey — Acarinida. 39 121 



Family HALACAEIDAE. 



Rhombognathus setosus (Lohm.). 



Clare Island, one specimen found amongst coralline seaweeds in July. 

 Distribution. — Eecorded by Lohmann from the Baltic (strand and littoral 

 regions to a depth of 19 metres, 44). 



Rhombognathus notops (Gosse). 



Clare Island, a few examples amongst coralline seaweeds, July. 

 Distribution. — Atlantic (ranging as far north as Greenland, 44). Baltic. 



Rhombognathus pascens (Lohm.). 



Clare Island, common in coralline seaweeds and in Lithothamnion, July ; 

 Blacksod Bay, on shore during March (Irish Fisheries Station W. 189). 

 Elsewhere on the Irish coast at counties Dublin and Cork. 



Distribution. — Atlantic, North Sea, and Baltic. Littoral regions down to 

 46 metres (44). 



Rhombognathus Seahami (Hodge). 



Clare Island, in coralline seaweeds and in Lithothamnion, July ; Blacksod 

 Bay, in Lithothamnion (Irish Fisheries Station W. 235). Has also been 

 found on the east coast at Howth and Sandycove in February and March. 



Distribution. — Similar to that of the preceding species. 



With regard to the relative numbers in which the species of this genus 

 occur I may mention that of 80 specimens obtained from a small quantity of 

 coralline seaweeds, 66 are referable to B. pascens, 10 toS.. Seahami, 3 to B. notops, 

 and 1 to B. setosus. 



Halacarus (Halacarus) actenus Trouess. 



Clew Bay, nymph dredged in 24 fathoms in May (Irish Fisheries Station 

 W. 84) ; Blacksod Bay, adult male in March, and nymphs in weed from the 

 shore, September (Irish Fisheries Station W. 234). Has also occurred adult 

 on a Holothurian at Portmarnock, on the Dublin coast, in February. 



Distribution. — Atlantic, evidently a widespread species in both the 

 northern and southern oceans, occurring as far south as Kerguelen. 

 Littoral region down to 500 metres. 



R.I. A. PROC, VOL. xxxi. R 39 



