Sarcoptiformes 323 



14. Cervical setae marginal, long, pilose; female genital opening be- 

 tween coxae in; male genital opening between coxae iv; tarsal 

 claws in larvae and nymphs single, normal; in adults claws dou- 

 ble, Y-shaped or forked on tarsi i and ii Lardoglyphidae 



Cervical setae marginal, minute, almost a curved spine; tarsi i-iii 

 each with three spoon-shaped or lanceolate setae; tarsus iv with 

 one such seta; tarsal claws with a ventral knob; body with three 

 pairs of long setae; adults not known, described from nymph 



Olafseniidae 



15. Male genital opening between coxae iii-iv 16 



Male genital opening between coxae i-ii; male with tarsal iv and 

 anal suckers; body acarid-like, but skin well sclerotized; dorsal 

 setae simple, very short; female genital opening between coxae 

 iii-iv Chortoglyphidae 



16. Skin dull, or roughened by numerous fine distinct points or scales; 

 body variously shaped; tarsi gradually tapering towards tip, with 

 caruncle, on distal half of which is claw, often minute; clublike 

 sensory setae on tarsi i and ii; dorsal setae usually pilose, feath- 

 ered, or fanlike Glycyphagidae 



Skin leathery or scaly; body depressed, round or oval, lozenge- 

 shaped or almost quadrangular; tarsi with pedunculate caruncle; 

 claw, which is often minute (and apparently absent at times), 

 wholly involuted in caruncle; tarsi i and ii without clublike sen- 

 sory sestae; dorsal setae simple Canestriniidae 



17. Movable chela sawlike; all legs of more or less equal size and 

 equally developed 18 



Movable chela not sawlike, enclosed in tube formed by palpi; legs 

 I and II with claws but no lobes; legs in and iv enormously devel- 

 oped into clasping organs without claws but with tarsi adapted as 

 claws; found on gills of crab Ewingidae 



18. Distal segment of palpus with two flagella; caruncle with sessile 

 claw Anoetidae 



Palpus with normal setae; tarsi with caruncles without claws; dis- 

 tal portion of tarsus clawlike Linobiidae 



19. With pair of anterior vertical propodosomal setae 20 

 Without vertical setae on propodosoma 21 



20. Skin smooth; body segmented between propodosoma and hystero- 

 soma; few long, simple setae; tarsi with sessile caruncles; free- 

 living mites Nanacaridae 



