Trom b idiform es 



225 



dosoma and the hysterosoma. The propodosomal shield is either weak 

 or entirely lacking as is usually the case. The peritreme is present at the 

 base of the chelicerae. There are two pairs of sensory setae on the pro- 

 podosoma. Two pairs of lenslike eyes may be found on each side of the 

 propodosomoa {Pseudocheylus), or two pairs of pigment spots with 

 a mutual cornea (Neocheylus), or 

 there may be no eyes. The palpi are 

 short and usually somewhat thicker 

 than the legs. The palpal femur is 

 longer than the other segments and 

 thickened on the outer side so that 

 the palpi are forceps-like. The pal- 

 pal tibia has a strongly bent claw, 

 and the ventral palpal tarsus is 

 weak (or entirely gone?). Tarsi of 

 the legs have either a long stalked 

 triangular caruncle or sucker and 

 no claws {Pseudocheylus, Neo- 

 cheylus), or have a bell-like car- 

 uncle or lobe between two claws 

 (Tarsocheylus) , or lack an empo- 

 dium and have normal but very 

 small claws on tarsi i and comblike 

 claws on the other tarsi {Stigmo- 



cheylus). No genital suckers are Figure 169 Pseudocheylus (Anop- 



present. The genus He.erocheylus ^^l ^aT Berf/seT^loT""" 

 has only one pair of propodosomal 



sensory setae. Tarsi i lack ambulacra, but ii, iii, and iv have caruncles or 

 lobes only. Tragardh 1950 has divided these mites into two subfamiUes. 



Key to the Pseudocheylidae 



(from Tragardh) 



1. Chelicerae stylet-like; palps with large, sharply pointed, dentate 

 terminal tooth and varying number of comb-shaped or sickle- 

 shaped setae; all legs with claws Pseudocheylinae 



Chelicerae with strongly curved, sharp terminal tooth of the same 

 type as in the larvae of the Trombidiidae. Palps with blunt, eden- 

 tate terminal tooth, no comb-shaped or sickle-shaped setae. Legs 

 I antenniform, legs n-iv with tooth-shaped, subterminal bristle and 

 large, disk-shaped empodium Heterocheylinae 



