268 ENTOMOLOGY FOR MEDICAL OFFICERS 



'Pedipalps minute, hardly visible ; cheliceras styliform ; female 

 only with a pair of spiracles in front of the anterior legs, and 

 with a pseudostigma and club-shaped bristle on each side just 

 behind the anterior legs Tarsonemida. 



Pedipalps small but distinct ; chelicerse generally pincer-like ; no 

 special breathing-organs ; female without pseudostigmatic 

 club = 12. 



Integument generally with fine parallel striae ; legs short ; parasitic 



Sarcoptida. 

 Integument not striated ; legs longer ; not as a rule parasitic 



Tyroglyphidce. 



fFour pairs of legs ; parasitic in sebaceous glands of mammals 

 2. \ Detnodicidce. 



[Two pairs of legs ; parasitic on vegetation Eriophyidoe. 



