39 78 Proceedings of the Royal Irish Academy. 



Paraseius serratus sp. nov. (PI. VI, fig. 23a-d.) 



As far as one can judge from a short description this species is allied to 

 a Xorwegian form Ameroseius borealis, Berlese (6, p. 259). It is a narrow, 

 straw-coloured mite, which would appear to possess characteristics in its 

 small size, the sculpturing of the dorsal shield, the form of the pedal plates, 

 and in other details. 



Female (fig. 23a). — Length 440/u, breadth 286^. Shape a long oval ; 

 dorsal shield large, surface transversely wrinkled in front with angular 

 marking at the shoulders and towards the sides, which are distinctly 

 serrated. Central hair armature weak, becoming stronger towards the 

 margins of the shield where the hairs are adpressed; frontal bristles 

 strong. Sternal plate wide in front, hinder corners rounded. There are two 

 small metasternal plates, each carrying a hair. Ventro-anal plate com- 

 paratively large, almost circular, with three pairs of marginal hairs. The 

 united pedal and peritrematie plates are produced in a broadly rounded 

 extremity well beyond the last acetabula: peritreme sinuate with a post- 

 stigmal continuation bordering, and apparently fused with, the outer margin 

 of the pedal plates. 



Capitulum transverse, hinder margin rounded, hairs normal ; epistome 

 (fig. 23d) trispinous, lateral spines with bifurcated tips ; maxillary lobes 

 lanceolate and well separated. Basal segment of palp swollen, armed with 

 two hairs, the inner one long and undulate. The tritosternum is remarkable, 

 instead of the usual narrow base and long filaments, the latter are welded 

 together, terminal part ciliated at the sides, with a brush of long bristles 

 at the extremity. 



The legs are comparatively shorter and stouter than in A. italicus, the 

 lengths are about 52S^, 418/i, 319p, and 396u. Ambulacra (fig. 23c) with 

 the upper lobe more acute, and the tarso-ambulacral hairs are much shorter. 

 The fixed chela has a group of at least five distinct teeth, while the free 

 chela has only one strong tooth. 



Locality. — Found commonly in sphagnum, gathered on the slopes of 

 Croaghpatrick at an elevation of about 600 feet, during the month of 

 October. 



Paraseias tenuipes sp. nov. (PI. VI, tig. 2-la-e.) 



The chief points in which the species differs from P. italicus are, the 

 larger size, the form of the pedal plates, the smaller anal shield. 



Female (tig. 24a). — Shape a broad oval, length 742^, breadth 490//. 

 Dorsal shield reticulated, with rather strong marginal hairs; there is a 

 circular prominence not far from its hinder margin. The sternum is very 



