324 Acarology 



Skin smooth, body segmented between propodosoma and hystero- 

 soma; propodosomal shield present; body setae few, tiny; tarsi 

 with bell-like caruncles on long stalks; free-living mites 



Hemisarcoptidae 



Skin with strong transverse striations; body without suture be- 

 tween propodosoma and hysterosoma; caruncles stalked, on short 

 legs; skin parasites Sarcoptidae 



21. Mouth parts well developed, chelicerae chelate for chewing 22 



Mouth parts reduced, specialized into sucking tube; small, hair- 

 less mite; tarsi with caruncles but without claws; in air sacks of 

 chickens and lung tissue of squirrels Cytoditidae 



22. Legs I and ii with caruncles 23 



Legs I and ii without caruncles but tarsi divided into clawlike 

 points; tarsi in and iv with caruncles; elongated mite; in subcu- 

 taneous tissues of fowl Laminosioptidae 



23. Caruncle or adhesive lobes on short or long stalks; caruncle of 

 normal size or even smaller, never greatly enlarged 24 



Caruncle not stalked, of monstrous size; tarsi in and iv with three 

 ventral, clawlike spines pointing to rear; on skin of small birds 



Heteropsoridae 



24. Tarsi i with caruncles 25 



Tarsi i without caruncles and shaped like anchor; with propodo- 

 somal shield; no suture between propodosoma and hysterosoma; 

 legs on anterior portion of body; tarsi ii, in, and iv without claw 

 but with adhesive lobe Myialgesidae 



25. Caruncles on all legs of females 26 



Tarsi ni of females ending in long whiplike setae; posterior margin 

 of male bilobate; usually skin parasites of mammals Psoroptidae 



26. Small mites with propodosomal shield; female rounded; male 

 bilobate on rear; larvae and nymphs with caruncles on all legs (?) 



Epidermoptidae 



Small mites with propodosomal shield; female rounded; male 

 bilobate on rear; larvae and nymphs with caruncles on legs i 

 and n only Psoralgidae 



27. Maxillae and legs normal, not modified for clasping hair 28 

 Maxillae or one or more pairs of legs modified into clasping organs 

 for grasping hairs of host Listrophoridac 



