Glare Island Survey — Acarinida. 39 97 



Oribata alpina sp. nov. (PI. VIII, fig. 32a, b). 



The following short description refers to an apparently undescribed species 

 of Oribata which is common enough in the mountain districts of the County 

 Mayo. It is unknown to Mr. Michael, to whom specimens were sent, and 

 it does not appear to agree with any of the European species of this genus 

 described since the publication of the " Tierreich " volume treating of the 

 Oribatidae. 



The species may be compared with Oribata mollicoma C. L. Koch, to 

 which it is allied in general structure. It is, however, much larger and of 

 more robust build and the hairs of the notogaster are shorter, other 

 differences are also noticeable. 



The measurements are: length 716ju, breadth 512yu. Colour pitchy 

 black with a lighter patch on the front of the body. The texture of the 

 epidermis is dull, due to the extremely fine and close punctuation of the 

 surface of the body. Cephalothorax rather narrow, rounded at the extremity. 

 Lamellae a pair of broad blades ending in stout bluntly pointed cusps, which 

 are bent downwards, and are separated by a cup-shaped hollow. The 

 translamella is a narrow band. As in the case of 0. mollicoma the end of the 

 lamellar region reaches far forwards so that the frons is very short. The 

 prostigmatic organ is moderately long with a stout stem and weakly clavate 

 extremity, directed upwards. Interlamellar hairs widely separated, long, and 

 finely setose. Notogaster globular with a double row of marginal hairs 

 and there are also three or four pairs on the back of the animal, these 

 hairs are rather stout, finely setose, and are much shorter than in 

 0. mollicoma. Front margin of the progaster gently rounded, sloping back- 

 wards towards the side margins. Pteromorphae normal, not produced in 

 front. Legs long and rather stout. Mouth parts of the usual type. 



This species may be easily separated from Oribata Edwardsi by the much 

 greater length of the lamellae. 



Localities. — Clare Island, in moss on Croaghmore mountain, August; 

 Lough Fenagh, in sphagnum, October ; Delphi, in moss, August. 



Oribata Edwardsi Nicolet. 



Clare Island, Aehill, and the Westport district, llather a common species 

 in moss and under bark from March to October, and doubtless throughout 

 the year. Also on the Dublin mountains and apparently widespread in 

 Ireland. 



Distribution. — Finland ; Sweden ; Germany ; France : Italy ; and 

 Britain, 



