DESCRIPTIONS OF GENERA AND SPECIES. 271 



Habitat. I have often found this species in con- 

 siderable numbers in moles' nests in England. I do 

 not think that any record exists of its having been 

 found by anyone else, but my friend Mr. E. Bostock 

 has found it in similar situations. I have not ever 

 found it upon the mole itself, nor have I found it any- 

 where except in the moles' nests. The nests must be 

 fresh and inhabited by the mole at the time. 



GLYCYPHAGUS DISPAR,* Michael. PL XV. 



Glyciphagus dispar, 1886. Michael, " On some IJndescribed Acari 

 of the Genus Glyciphagus found in Moles' 

 Nests," in ' J. Linn. Soc.,' vol. xix, p. 280, 

 pi. xxxv, figs. 617. 



Glycyphagus dispar, 1898. Berlese, ' A. M. S. Crypt.,' p. 106. 



1899. Kramer, ' Thierreich,' Lief. 7, p. 145. 



Female. Male. 

 Average length about . . "35 mm. *17 mm. 



breadth about 



length of legs, first pair 

 ,, second pair 



,, ,, third pair 



,, fourth pair 



24 

 16 

 14 

 13 

 19 



13 

 10 



08 

 09 

 09 



The most striking character of this very singular 

 species is the extreme dimorphism between the sexes ; 

 this is carried to an extent far beyond any sexual 

 differences found in any other species of the Tyrogly- 

 phidaB ; indeed, the two sexes would not ever have 

 been supposed to belong to the same species, or even 

 genus, if they had not been taken in copo. 



Colour when just emerged white ; afterwards the 

 female is reddish brown ; darker and redder than that 

 of Gr. platyg aster. The spaces on the underside, 

 enclosed by the sclerites surrounding the genital and 

 anal regions, remain pure white. The male is dull, 

 light grey, considerably lighter than the female ; 

 sometimes without and sometimes with the red shade 

 of the female. 



Texture of the female very similar to that of 



* Dispar, unlike. 



