39 106 Proceedings of the Royal Irish Academy. 



JVothru-s invenusttts Michael. 

 Not uncommon under lichens growing on large boulders on the south 

 shore of Howth, near the Bail}' lighthouse, county Dublin. 



Nothrus horridiis (Herm.). 

 The nymphal form has been found on Lambay, county Dublin. 



Nothrus teleproci-us (Herm.). 

 Abundant under stones amongst heather on Lam bay and also at Howth, 

 county Dublin. 



Malaconothrus glaber (Michael). 



Westport, common on the slopes of Croaghpatrick in wet sphagnum, 

 October. 



The statement that the cuticle of this species is " smooth, but not shining, 

 without any reticulations " 48, p. 525) must be understood in a comparative 

 sense. In a note received from Mr. Michael he remarks "the word smooth 

 in my description (British Oribatidae) must be taken only as compared with 

 reticulated. I give ' not reticulated ' in a bracket as the equivalent and 

 explanation of ' smooth.' When there is an entire absence of all punctures 

 and granulations I use the word ' polished.' " It seems worth emphasizing 

 this point as in one or two recent descriptions of allied continental species it 

 seems to have been misunderstood. As a matter of fact in the present 

 species both the eephalothorax and the abdomen are exceedingly finely 

 punctured, and there are also numerous light-refracting punctures. 



Malaconothrus was introduced as a new sub-genus by Berlese with 

 M. egregia as the type species, it would really seem to be worthy of generic 

 rank on account of the structure of the legs, and also of the pseudostigmatic 

 area. Berlese gives a very short diagnosis which is as follows " Organa 

 pseudostigmatica setula nulla vel iuconspicua aueta. Pedes curti, crassiusculi, 

 tarsis apice spinis validis armatis " (7). 



Distribution. — England ^amphibious, in moss and sphagnum, Miciiael) ; 

 Scotland (Evans). An allied species M. sphagnicola, Tragardh, has been 

 recorded from Swedish Lapland (88). 



Malaconothrus tardus (Michael). 



Clare Island (Croaghmore), and on Croaghpatrick. Evidently rather a 

 common species in sphagnum in both of these localities. 



In these specimens the anterior side corners of the. abdomen are almost 

 square and do not form rounded projections. This refers, however, to dead 

 specimens, and Mr. Michael remarks in lit. that in these the appearance of 



