Clare Island Survey — Acarinida. 39 25 



Ranunuculus, June, 1909 ; nymph in Castlebar Lough, June, 1909. Elsewhere 

 in Ireland I have found this species in a pond on the bank of the Eiver 

 Corrib (close to Galway, June, 1903) ; and it also occurs in lakes in the 

 Killarney district. The specimens of Frontipoda taken in the eastern parts 

 of Ireland are all to be referred to the common F. musculus, so that the 

 new species would appear to have a western range in Ireland. 



Oxus plantaris Sig. Thor. (Plate II., fig. 21 a-c.) 



Bog pool in Cartron Mountain, near Letterfrack, County Galway, March, 

 1904. 



A female Oxus collected in this locality by Mr. S. W. Kemp is apparently 

 to be referred to 0. plantaris Sig. Thor, a species which has hitherto only been 

 recorded from Norway. In his short description of the species, Thor 

 compares it with 0. ovalis, which it resembles in size, shape, and colour. 

 The characters by which he distinguishes it are the spines on the first pair of 

 epimera, and the peculiar shape of the genital discs. 



The Galway specimen is the only representative of the genus Oxus hitherto 

 found in Ireland. It is preserved in balsam, so that the exact size cannot be 

 given. The colour of the living mite is noted as reddish-brown, with a 

 darker central dorsal area, and the legs are slate-coloured. 



The epimeral region is shorter and broader than in female ovalis ; and the 

 posterior concavity to receive the genital area is a little wider, with more 

 bluntly rounded corners. The first epimeral process is longer and more 

 slender, with a distinctly sinuate inner margin. In this respect it would 

 appear to resemble 0. auadriporus Piersig (12, fig. 116 b). Unfortunately the 

 terminal spine-armature is damaged in the Irish specimen, and only one of 

 the modified spines remains at the apex of each. This is, however, the long 

 claw-shaped spine (PI. II., 21 c), described and figured by Thor as one of the 

 characteristics of the species. 



The genital area lies deep in the epimeral region. A decided difference 

 from 0. ovalis will be noticed in the peculiar shape of the genital discs. These 

 have remarkably small external apertures, with the chitinous basal part much 

 larger ; and in the case of the first two pairs these bases are acuminate at 

 the extremities. Thor points out their resemblance, in this respect, to the 

 discs of Lebertia brevipora. 



The palps are longer than in 0. ovalis; they measure about - 235 mm. in 



length. Two long, stout spines spring from the upper distal extremity of the 



second segment. Two rather similar spines are situated near the middle of 



the third segment on the dorsal side, and there is a long, fine hair at the 



B.I.A. puoc, vol. xxxi. D 39 



