568 ON BRITISH MITES OF THE FAMILY ORIBATIDiE. [DeC. 12, 



Claws monodactyle. Pseudostigmatic organs long and fili- 

 form. 



Nymph and larva unknown. 



This fine species is closely allied to iV. targionii Berlese, but 

 may be distinguished from it by the much longer, loavy, un- 

 pectinated hairs on the notogaster. The apophyses from which 

 these hairs spring are very small, while in N. targionii they are 

 exceedingly conspicuous. 



A single example was sent by Mr. W. Evans, taken at Loch 

 Gaily, Fife, in May 1905. Another specimen was found by us in 

 Sphagnum from Blairgowrie, Perthshire, in November 1905. 



This species, even more strongly than N'. targionii, recalls 

 Hermannia bistriata, and in these three forms the two genera 

 appi'oach one another very closely. 



NoTHRUS TECTORUM Berlese. (Plate XX. fig. 4.) {Hypocthonius 

 tectorum Berlese, Acari Myriapoda et Scorpiones etc., fasc. 78, 

 no. 8, 1896.) 



This species, which we at first regarded as new to science and 

 which may be easily recognised from the figure (PL XX. fig. 4), 

 is no doubt identical with the Hypocthonius tectorum of Berlese. 

 That arachnologist has, we believe, been misled by an apparent 

 segmentation artificially produced by slight pressure in mounting. 

 We have examined many living specimens, and specimens mounted 

 without pressure, and these present no trace of segmentation ; 

 but we find that a transverse furrow (varying slightly in position 

 and width) is readily produced in the soft integument when the 

 cover-slip is allowed to press somewhat heavily upon it. The 

 species must therefore be removed to the genus N^othrits, to 

 which it undoubtably belongs. 



Xot rai'e in moss from walls and house-roofs at Grantchester, 

 Cambridge. 



NoTHRUS CRASsus, sp. nov. (Plate XX. fig. 5.) 



Length 500 yu. Coloxn* light yellow- brown. Integument smooth 

 and veiy imperfectly chitinised. Claws tridactyle. Pseudostigmata 

 fairly large but not very projecting. Pseudostigmatic organs 

 spindle-shaped, often directed backwards, and rather large. 

 Genital and a.nal plates large and close together. 



An aquatic or amphibious species occuiring in Sphagnum in 

 heath-pools near Bournemouth, in company with iV. glaher and 

 N. monoclactylus. 



Of the not very well-defined genus Nothrus the five species 

 tecto?'um, tardus, glaher, mo7iodactylus, and crassus form a compact 

 gi'oup, agreeing in the I'ounded form of the abdomen and in their 

 very slight degree of chitinisation. Tectorum and tardus are 

 terrestrial species, while the other three always occur in or near 

 water, and in glaher and monodactylus the pseudostigmatic organs 

 are absent. 



