ON SOME NEW ACARINE PARASITES OP RATS. 



185 



cJ. Style of chelicera not very long and very like that of L. echidninus in appearance. 

 Ventral plate shaped as shown in figure 2 ; there are eleven pairs of slender setae on 

 it and they are all fairly long, except the last pair ; the usual unpaired hair is also 

 present. Peritreme apparently almost as long as in the female. Length of body 

 •45 mm. ; the width "27 mm. 



Ceylon : Colombo, a number of specimens from Mus rattus and M. norvegicus 

 (Dr. L. F. Hirst) (the types). India : Calcutta, specimens found on Nesokia 

 (Gunomys) bengalensis, 22.iii.15, and on Mus rattus, 10.iii.15 (C Paiva). Sierra 

 Leone: Freetown, numerous specimens taken on Mus norvegicus, xi.l914 

 {A. W. Bacot). Dutch Guiana : Paramaribo, a number of examples from 

 Mus norvegicus, 27.vii.08; presented to the Quick Laboratory, Cambridge, by 

 the Hon. N. Charles Rothschild, and kindly lent me for examination by 

 Prof. G. H. F. Nuttall, F.R.S. 



Dermanyssus murls, Hirst. 



Additional locality. Central Formosa (Hoist Coll.) ; host not given. 



Genus Microthrombidium, Haller. 

 Microthrombidium gliricolens, sp. nov. (figs. 3, 4). 



Fig. 3. Microthromhidium gliricolens. Hirst, sp. n. ; dorsal aspect. 



Dorsal surface. Scutum much wider than long (width '069 mm., length '04 mm.), 

 its anterior edge straight, but the posterior edge distinctly curved ; seven hairs are 



