28 STUDIES ON ACART. 



fi. DEMODEX BOVIS, Stiles, 1892. 



T>. foUiculorum var. bovis, Stiles, Canad. Ent. 1892, vol. xxiv. p. 28G. 

 D. bonis, Canesti-ini, Prospetto dell' Acarofauna Ital. 1899, part 8, p. 9G7. 



(Plate I. fig. 6 ; Plate II. figs. 7 & 8 ; Plate V. figs. 25, 2G ; 

 Plate VI. fig. 30.) 



2 . D. hovis is a short and fairly wide species, closely resembling 

 I), equi in general appearance and also rather like I), phylloides. Body 

 from a little more than three up to more than three and a half times 

 (rarely up to nearly four times) as long as wide. Abdomen a little 

 longer than cephalothorax + capitulura, the end being distinctly pointed 

 and sometimes almost tail-like. Capitulum short and wide, being much 

 wider than long; spines on its dorsal surface rather short, a little 

 curved and pointed. 



(S . Male usually a little larger than female, and with a most distinct 

 caudal process. Body 3 J up to 3 1 times (or even 4 times, but this is 

 exceptional) as long as the width ; the abdomen usually ends in a short 

 but distinct tail-like process, and is considerably longer than cephalo- 

 thorax + capitulum. Waist or constriction between cephalothorax and 

 abdomen often well-marked. Penis rather long ; it has a short enlarged 

 basal portion and the slender distal part is bifid, consisting of two 

 blanches, one of which ends in a very fine and sharp point, the other is 

 wider and more blade-like, being more strongly chitinised and blunter 

 at the tip. Genital opening of male above and in front of the 

 groove between coxae (epimera) of first and second legs. The operculum 

 consists of a median triangular lobe and two small lateral lobes between 

 which the penis is extruded. 



Beutonymph. The final nymph containing the developing last stage 

 (adult) reaches a large size in this species, being very elongated and 

 from less than four up to slightly more than five times as long as wide. 

 The anterior part of the body is rather wide, but the posterior end is 

 much narrowed so as to form a long slender tail. Palp with the last 

 segment conical and bearing three or more strong claw-like spines at 

 the end. The four pairs of lateral platelets or epimera are not very 

 distinct in preserved specimens ; they each bear exceedingly minute but 

 distinct little cones furnished with three or more sharp denticles. A 

 little to the inner side of these epimera there are the usual two series 

 of four little discs with the posterior margin curved. 



E(jg oval in shape. 



