ACAEID^. 667 



pici-pubescentis, has an elongated, oblong, flattened body, with 

 four short legs, provided with a few bristle-like hairs, and end- 

 ing in a stalked sucker, by aid of which the mite is enabled to 

 walk over smooth, hard surfaces. The body is square at the 

 end, with a slight median indentation, and four long bristles of 

 equal length. They remained motionless in the groove on the 

 barb of the feather, and when removed seemed very inert and 

 sluggish. The male (Plate 13, fig. 3) is a most singular form, 

 its body being rudely ovate, with the head sunken between the 

 fore legs, which are considerably smaller than the second pair, 

 while the third pair are twice as large as the second pair, and 

 directed backwards, and the fourth pair are very small, not 

 reaching the extremity of the body, which is deeply cleft, and 

 supports four long bristles on each side of the cleft, while other 

 bristles are attached to the legs and body, giving the creature 

 a haggard, unkempt appearance. The genital armature is 

 situated between the largest or third pair of legs. A preced- 

 ing stage of this mite, which may be called the pupa, is repre- 

 sented on Plate 13, fig. 2. It (all the figures of this sarcoptid 

 being drawn to one scale by Prof. A. M. Edwards, 

 and magnified one hundred and fifteen diameters) 

 looks somewhat like the adult, the body being shorter 

 and broader, but without any genital armature. 



We figure on Plate 13, figs. 8 and 9, greatly en- 

 larged, a most remarkable mite, discovered by New- 

 port on the body of a larva of a wild bee, and 

 described by him under the name of Heteropus ven- 

 tricosus. Fig. 8, in the plate, represents the body 

 of the fully formed female. In this stage it reminds us F te- 642. 

 of Demodex and the Tardigrades. After attaining this form 

 its small abdomen begins to enlarge until it assumes a globu- 

 lar form (Plate 13, fig. 9) and the mass of mites look like little 

 beads. Mr. Newport was unable to discover the male, and 

 thought that this mite was parthenogenous. Another singular 

 mite is the Demodex folliculorum (Fig. 642), which was dis- 

 covered by Dr. Simon, of Berlin, buried in the diseased folli- 

 cles of the wings of the nose in man. It is a long, slender, 

 worm-like form, with eight short legs, and in the larval state 

 has six legs. This singular form is among the lowest and 



