434 On Three new Parasitic Acart. 
rather different in this new Demodew, for there is a slight but 
distinct constriction or waist at the point where the abdomen 
joins the cephalothorax. Width of cephalothorax a little 
more than four times up to four and a half times the total 
length of the body (incl. capitulum). Cephalothorax + 
capitulum a little less than the length of the abdomen. 
Capitulum rather short, 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 
curved. Penultimate segment of palp salient and pointed 
laterally, as in D. musculz. 
Measurements.—Total length (incl. capitulum) 173 yp; 
length of cephalothorax + capitulum 85 mw, of abdomen 98 p ; 
greatest width of cephalothorax 39-41 pw, of abdomen 84 p, 
of capitulum (at base) 27 w; length of capitulum 20 yp. 
Material.— Three dormice (Muscardinus 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 ?.) 
9.—The Demodex occurring in the hedgehog is an elon- 
gated form closely resembling that» of the dog (D. caninus) 
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 
slightly wider as in, J). eaninus ; the sculpturing of the dorsal 
surface of the capitulum apparently is also rather different ; 
the two spines are very like those present in J). 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 coxe of the fourth pair 
of legs, the first striation being deep and well-defined. 
Measurements.—Total length 313-335 uw ; length of cephalo- 
thorax +capitulum 108 yp, of abdomen 205 w; greatest width 
of cephalothorax 44 wu, of abdomen 46 mw, of capitulum (at 
base) 35 w; length ot capitulum 26 pw. 
Material.—Several specimens from an English hedgehog. 
