THE GENUS DEMODEX. 



35 



Oudemans gives the following measurements for this variety : — 



Female. 



Total length of body -ISO mm. 



Width of body -027 „ 



Length of capituluin '022 „ 



„ thorax "050 „ 



Host: House Mouse {Mus muscidus). A number of specimens from tame mice. 



DEMODEX ARVICOL^ var. APODEMI, Hirst, 1918. 

 Demodex apoiUmi, Hirst, Ann. Mag. Nat. Hist. (ser. 9) vol. ii. 1918, p. 145. 



(Plate X. figs. 43-45.) 



2 . A very minute but fairly elongated species. Body about 4^ 

 times as long as the greatest width of the cephalothorax. Abdomen a 

 little less than twice the combined length of cephalothorax and capi- 

 tulum. Capitulum (at base) wider than its length. Spines on dorsal 

 surface of capitulum well developed, being pointed at the end, as in 

 var. muscuU, etc. 



d . Body from a little more than four up to about five times as long 

 as width of cephalothorax. Abdomen about as long as cephalothorax+ 

 capitulum. Capitulum when fully extended, about as long as wide. 

 Male sexual aperture above interval between second and third pairs of 

 legs. Penis fairly long and slender. 



Author's measurements : — 



Total length of body (inch capit.) . . 

 Length of cephalothorax + capitulum 



,, abdomen 



Greatest width of ce])halothorax . , 



„ „ abdomen . . . . 



„ „ capitulum (at base) 

 Length of capitulum 



„ ovum (in body of female) 

 "Width 



Host : Field Mouse (^Apodtmus sylvaticus). 



DEMODEX AEVICOLiE var. GLAEEOLI, var. nov. 

 (Plate XL figs. 49, 50.) 

 $ . Proportions very much the same as in slender specimens of var. 

 mnsculi. Body about 5^-5f as long as the cephalothoracic Avidth. 

 Abdomen a little longer than cephalothorax + capitulum. Capitulum 

 fairly elongated, being about as long as wide; spines ou its dorsal 

 surface much like those of var. mnsculi in shape. 



