431 On Three neio Parasitic Acari. 



ratlier different in this new Demodex^ for there is a sliglit but 

 distinct constriction or waist at tlie point wliere the abdomen 

 joins the cephalothoiax. Width of cephalothorax a little 

 more than lour times up to four and a half times the total 

 length of the body (incl. capituhim). Cephalotiiorax + 

 capitulum a little less than the length of the abdomen. 

 Capituluni rather sliort, being wider than long (at the base) ; 

 the oval internal portion is rather narrow, however. Spines 

 on dorsal surface of capitulum fairly well developed and 

 cuived. Penultimate segment of palp salient and pointed 

 laterall}', as in D. muscuU. 



Measurements. — Total length (incl. capitulum) 173 yu- ; 

 length of ceplialotiiorax + capitulum 85 fi, of abdomen 98 ^ ; 

 greatest width of cephalothorax 39-41 /a, of abdomen 34 /li, 

 of capitulum (at base) 27 /*; length of capitulum 20 /x. 



Material. — Three dormice (^Muscardiniis avellanarius) were 

 examined for Demodex, and all of them were found to be 

 infected, but the parasites were few in number. 



Demodex erinacei, sp. n. 

 (Var. of D. caninus?.) 



$ . — The Demodex occurring in tiie hedgehog is an elon- 

 gated form closely resembling tliat of the dog {D. canimis) 

 in almost every respect, but of larger size and with the 

 capitulum wider as compared with its length, being very 

 distinctly wider than long (at the base), instead of only 

 slight]}^ wider as in D. caninus ; the sculpturing of the dorsal 

 surface of the capitulum apparently is also rather different; 

 the two spines are very like those present in P). caninus, 

 being quite short. Body from over six to slightly more than 

 seven times as long as wide. Cephalothorax + capitulum 

 about a third of the total length. Transverse striations of 

 body extending forwards beyond the coxre of the fourth pair 

 of legs, the first striation being deep and well-defined. 



Measm'ements. — Total length 313-335 /j, ; length of cephalo- 

 thorax + capitulum 108 /jl, of abdomen 205 /j. ; greatest width 

 of cephalothorax 44 /u,, of abdomen 46 fx, of capitulum (at 

 base) 35 /n; length ot capitulum 26 fi. 



Material. — Several specimens from an English hedgehog. 



