39 120 Proceedings of the Royal Irish Academy, 



Distribution. — Norway, and a variety (trispinum Berl.) has been described 

 from Germany (16). 



Microthrombidium calycigerum Berl. 



Found in the same locality as the preceding species. 



This species is remarkable for the peculiarly modified body hairs. These are 

 very strongly clavate and finely setose, with a septate extremity, and though 

 of similar type throughout, they vary considerably in length in different parts 

 of the body. All of these hairs spring from beautifully formed stellate 

 bases. 



The form of the body of this species is rather elongate, the Irish specimens 

 varying in length from 14^3^ to about lSOO/x, breadth about 1000^. The 

 length of the first tarsus is 3-iQ/u, breadth, 115//, thus agreeing closely with 

 the measurement given for this species by Dr. Berlese. On the last palp 

 segment there are five stout spines arranged along the outer side close to the 

 appendage. 



Distribution. — Norway. 



Microthrombidium subrasum Berl. 



Clare Island, a single fully grown specimen found in June. 



A species having an extremely dense covering of almost globular, papilla- 

 like hairs. The measurements differ only slightly from those of the type 

 form. 



Distribution. — Germany ; Italy ; Britain. 



Sericothrombium holosericeum (Linn.). 



Clare Island, A chill Island, and the Westport district. 

 Distribution. — Found throughout Europe. 



[Thrombidium (?) fucicolum Brady. 



Under this name Brady has described an acarid which was " washed 

 from among the roots of Algae gathered between tide-marks in B,oundstone 

 Bay " (19). In a later reference (20) he changes the name to Thrombidium 

 fuscum, and remarks that it was subsequently jfound in fresh water. The 

 Irish localities mentioned are " Bog-pools near Clifden (Connemara), ditches 

 (slightly brackish) near Newport (Mayo), Kinny Lough (Donegal)." The 

 description of this acarid is unsatisfactory and leaves many points in doubt 

 so that the true identity of the creature does not appear to have been 

 settled. The rough figure accompanying the original description somewhat 

 suggests one of the sub-aquatic oribatid mites. It certainly does not belong 

 to the genus Thrombidium.] 



