Clare Island Survey — Acarinida. 39 53 



is clearly intermediate between Gamasus robustus and Gamasus lapponicus, 

 differing from both of these species in the armature of the second legs, and 

 in the male chelicerae. A notable feature is the presence of a sharply pointed 

 process on the inner margin of the maxillary lobes. 



Male, length about 800//. Femoral process of the second legs (fig. 3«) 

 long, comparatively straight and bluntly pointed; immediately in front of 

 this there is a broad knife-like process ; the outer distal margin of the 

 segment is bordered with a chitinous ridge, which is produced at one end in a 

 blunt point ; patella unarmed, except for a long ventral bristle. On the tibia 

 there is a discoidal prominence, which appears in side view as a crescentic 

 ridge. On the outer side of this there is a long bristle, bent at the tip. 

 Trochanter of the fourth pair of legs strongly convex on its dorsal side, and 

 there is a rounded ventral prominence (fig. 36). 



Capitulum as in the allied species, hair armature of the maxillary plate 

 consisting of four pairs of long bristles, three of which are placed near the 

 base of the maxillary lobes. The latter are moderately sinuate, armed on the 

 inner side with a sharply pointed spur (fig. 3c). Chelicerae robust; fixed chela 

 armed beyond the middle with one blunt tooth, behind which are three or 

 four extremely minute teeth; free chela also with one strong tooth (fig. 3d). 



Locality. — Under stones on the shore of Castlebar Lough, Co. Mayo, 

 July. 



Gamasus (Pergamasus) lapponicus Tragardh. 



1910. Tragardh 88, p. 408. 



Clare Island, $ in moss, July ; Achill Island, $ and $ , under bark and 

 fallen fir-cones, September ; "Westport district, under bark ; Knappagh Wood, 

 S S , August ; Lough Fenagh, $ , $ , October ; Croaghpatrick, <J , immature, 

 October. 



Apparently a common species in the district ; both sexes were usually 

 found in moss gatberings in company with G. robustus Oudms., to which 

 species it is allied ; it is, however, a smaller mite, and the armature of the 

 second legs is characteristic. I have also found it at Glendalough, Lambay 

 Island, and elsewhere in the Dublin district. 



Distribution. — Swedish Lapland (Sarekgebirge, Tragardh). 



Gamasus (Pergamasus) processiferus sp. nov. (PL IV, fig. ia-c.) 



This species is allied to G. decipiens and G. lapponicus, differing from both 

 in the armature of the trochanter of the fourth legs, also in the chelicerae 

 and the structure of the area genitalis. 



R.I.A. PROC, VOL. XXXI. H 39 



