194 



SOME BRITISH EARTHMITES. 



TrombMiidse. 



(plate X.) 



C. F. GEORGE, M.R.C.S. 



Ottonia conifera. — This mite is somewhat heart shaped, being 

 much wider in proportion to its length ; it is comparatively 

 small, not more than half the size of hullata. Mr. Soar's 

 measm"ement is — length, 1.76 mm. The colour is orange red, 

 and the legs of the usual formation in these mites, the front leg 

 being the longest ; the last joint being somewhat clubbed. The 

 palpi have two claws at the end of the fourth joint, and the fifth 

 is bag shaped and rather small (fig. c). The eyes are prominent 

 at the side of the cephalothorax, and have two ocelli each. The 

 most remarkable point is the structure of the hairs, or papillae 

 of the back. I was fortunate enough to isolate and mount one 

 of these, in good condition, attached to its socket. Mr. Soar 

 has given a good drawing of this, highly magnified (fig. f.). 

 It consists of a cone, apparently hollow, covered with very fine 

 hairs, projecting to a point, and set in an ornamental socket, 

 like a candle in its stick. Of course these papillce when com- 

 pressed are liable to open out somewhat, and become more cup- 

 shaped, and the fine terminal hairs break off at the curved line, 

 near the distal end of the papilla (fig. f.). Mr. Soar found the 

 mite in moss at Oban ; and Mr. Evans sent me one found by 

 him in a mole's nest early in 1908. 



Ottonia evansii. — I have named this little creature in honour 

 of the finder, Mr. Wm. Evans, of Edinburgh, to whom I am in- 

 debted for this and other specimens of this beautiful and interest- 

 ing group of mites. In size it is rather small, and in general shape 

 much like other members of this group ; the eyes are situated on 

 the shoulders, one on each side, embedded in the skin, each hav- 

 ing two ocelli. The fourth joint of the palpus has, besides the 

 terminal claw, a smaller accessory one, not shown in the 

 figure. The fifth joint is small, and differs considerably in 

 shape from the others already figured, seeming to oppose the 

 claw at the end of the fourth joint, and thus make a forceps 

 (see Mr. Soar's figure h.). The legs are covered with very fine 

 hairs ; the front ones are the longest, and have the terminal 

 joint thicker and club-shaped (figure c), the last joint of the 

 fourth pair is rather slender (fig. d.), the hairs are not barbed. 

 The hairs or spines on the body are simple, rather short, and 



Naturalist 



