Cooley & Kohls: Argasidae of N. America, etc. 



Ill 



Nymph 



From material before me there appears to be only one nymphal stage. Body elongate, 

 sides subparallel, and strongly constricted in front. Length (unfed) 2.88 mm.; extreme 

 width 1.6 mm. Coxal and supra-coxal folds well developed; median and transverse 

 post-anal grooves distinct; preanal groove present but not so well marked as in adult; 

 integument has lost all indications of parallel transverse striations (so prominent in 

 larvae) except at anterior end and now appears distinctly mammillated with minute 

 spines between mammillae. Capitulum located in a deep camerostome as in adult ; 

 hypostome appears as a very thin, slightly chitinized membrane with only minute 

 denticles arranged in transverse rows on apical portion (fig. 4, c) ; chelicerae elongate. 



Fig. 50. Distribution of Ornithodoros azleci Matheson. 



