39 92 Proceedings of the Royal Irish Academy. 



Urodinychus punctatissimus sp. nov. (PL VII, fig. oOa-b.) 



This species is allied to Urodinychus ovalis (Koch) with which it agrees 

 closely in form, size, and in general structure. 



Female (fig. 30a) Length 614^, breadth 486^, shape oval, dorsum 

 slightly convex. The entire surface of the body is exceedingly closely and 

 minutely punctured, so that a fairly high magnification is necessary in order 

 to make clear the individual punctures, and without a trace of the stronger 

 puncturation present in U. ovalis. The dorsal shield is crowded with short 

 hairs. Marginal shield very narrow, entire, with a row of widely separated 

 hairs, inner edge weakly crenulate, there are no cross striations. 



Camerostoma small. Genital area (fig. 306) as in U. ovalis, pointed in 

 front, surface of plate very minutely punctured. Ventro-anal plates com- 

 pletely fused, studded with hairs, but not so thickly as the upper surface of 

 the body. Fossulae pedales and metapodia like those of U. ovalis, as figured 

 by Berlese (1, Fasc. xli, No. 9). Peritreme with two loops, stigmal extremity 

 directed inwards, with a post-stigmal continuation in the fossulae of the 

 third legs. 



Locality. — Achill Island, a single specimen in moss, November. 



Urodinychus campomolendina Berl. 



Under bark in the Westport district, July. 



I have found this species commonly under bark of decayed tree trunks in 

 the Dublin and Wicklow districts. 



Distribution. — A widespread European species. 



Urodiscella philoctena (Trouess.). 



1902. Uropoda philoctena Trouessart 96, p. 36. 1904. Berlese 12, 



p. 342. 



A single male example occurred in a nest of the small yellow ant Lasius 

 flavus, in company with the following species, at Westport, Co. Mayo. 



M. Janet was the first to use the specific name "philoctena" accom- 

 panying his reference to the mite is a sketch of a male Urodiscella attached to 

 the strigil of an ant {Lasius mixtus). However, as he gave no description of 

 the animal, the name remained a nomen nudum until Trouessart subsequently 

 described the species. Janet's figure gives a very good idea of the under side 

 of the male, except that the peritreme is not included. 



I have also found the male and female of this species in nests of Lasius 

 flavus at Glendalough, and can state that the peritreme is similar in both 

 sexes. It is shaped almost exactly like a note of interrogation, differing, in 



