NO. 1382. THE ACARIXA OR MITES— BANKS. 59 



The Derniunvssidtr, though differing much in general uppearance 

 from the Ganiasida^, are elo^iel}' allied by .structure, and their para- 

 sitic habits are the best character for the separation. Probal)ly it 

 would be better to at)andon the group. The principal genera can l)e 

 arranged as follows: 



1 . Anal plate present ( Dermanyssina' ) 2 



Anal plate absent ( Halaraclmina' ) 5 



2. Body short; legs very stout, hind jxiir reaching mucli Ijeyond the tip of body. 



Body longer; hind legs not reaching beyond tiie tip 'A 



3. Peritreme on the dorsum, very short; body very distinctly constricted. /^/*7oj///.s-.>;r(.>< 

 Peritreme on venter, longer; body not distinctly constricted 4 



4. ]Mandil)les in botli sexes chelate; parasitic on bats and mice LiixDii/y.^u.f 



^Mandibles in male chelate, in female long, styliform; parasitic on l)irds. 



Dermanyssus 



5. Dorsal shields present; coxge clo.se together; living in seals Ilalantdnie 



No dorsal shields; hind coxee separated from the fore; living in monkeys. 



Pnannoruinsiis 



Pteroptiis^ which is parasitic on bats, is remarkable on account of 



Fig. 106. — L.ELAPS macropilis and caronx'le of 



TARSUS IV. 



Fig. 107.— Macrocheles caroeine.\.sis, 



FEMALE. 



its curious shape, dorsal position of the stigmata, and also on account 

 of the young hatching with the full complement of legs, the larval 



