NO. 1382. 



THE ACARINA OR MITES— BANKS. 



21 



with veiy .short, stout le^-s, each ending in two stout claws. It ha.s 

 since been found in various parts of P^urope, and was described by 

 Michael under the name of G<>inoiii<rus iuksckU/ihs. 



The genus Mii<>l>'ni was based on a species from the head of the 

 house mouse. All the legs are very short and thick, but the lirst pair 

 is heavier than the others and transformed into an organ fitted to 

 grasp the hair. The eggs are fastened to the hair of the mouse. The 

 nymph ditlers considerably from larva and adult in legs and beak. 

 The palpi are atrophied. In this stage it burrows into the hair folli- 

 cles, feeds there, and transforms. It is not supposed to suck ])lood, but 

 to feed on matter secreted l)y the skin cf the host. Several other 

 species are found on allied mammals, and one infests bats. Osborn 

 has recorded the presence of JA untscnll in this country. 



Plcol/K and S>/rhi<j(>j)Ji!I>is are closely allied. They have elongate 

 bodies provided with long bristles. They live in the quills of the 

 feathers of various birds, coming out only for breeding and migration. 

 One of these was recorded from Arizona by Hancock as Plcol'la ■vllJosd^ 

 wdiich Trouessart states is the same as S. hipecttnatus Heller of Europe. 

 Trouessart also claims that this is not an adult mite, Init that it is a 

 stage (which he calls "'s3'ringobiar') in the life of a Cheyletlella. 

 Norner, however, describes and tigures the male and egg of this species. 



Family ERYTHR.EID.E. 



There are few species of mites in this family, but one is very com- 

 mon and beneficial. They are at once separated from all other Trom- 

 bidoidea in that the coxte are close together and arranged in a radiate 

 manner. The ho([\ shows no complete division 

 between cephalothorax and abdomen, although 

 in the typical genus the division is often indi- 

 cated just behind the third pair of legs. The 

 body, which is usually short and broad, is 

 provided with many stout bristles. In front 

 on each side are one or two simple eyes. The 

 mandibles are quite large and prominent and 

 taper to a point wdiich is tipped by a curved 

 claw. The palpi are prominent, but slender; 

 in ErytJu'^us with a long "thumb," but in 

 Anydla the last joint is terminal. The legs 

 are large and long, gradually tapering and 

 provided wdth man^^ long hairs or bristles. 

 They are six or seven jointed, and terminate in tw^o or three claws. 

 In some species the tarsus is divided into a number of small joints. 

 On the venter are genital and anal openings, both quite elongate. 

 The young resemble the adult, except in having but six legs. . 



Fig. 23.— Venter of anystis. 



