Ewing — Neiu North American Acarina. 55 



beak and possessing a long digit at its distal end on the inner dorsal 

 aspect, from which springs a stout, pectinate bristle slightly longer than 

 the digit itself; third segment short, as broad as long and with a promi- 

 nate, stout, pectinate bristle on its outer margin, about twice as long as 

 the segment itself; distal segment ending in a large, simple claw about 

 twice as long as the segment itself, and with a single bristle on its inner 

 margin; papilla small and bearing two slightly curved serrulae, the 

 outer of which is slightly the longer, and two somewhat longer and more 

 strongly curved, simple bristles. The outer serrula is about three- 

 fourths as long as the claw of the distal segment. 



Abdomen short; possessing four rows of scales similar to those of the 

 cephalothorax; three scales in each of the two inner rows and four in 

 each of the outer rows. 



The anterior pair of legs is very much elongated, being longer than 

 the body of the mite and about twice as long as the second pair. Tar- 

 sus of leg I about two-thirds as long as the tibia, swollen distally and 

 terminated by two long bristles both of which are longer than the seg- 

 ment itself, the inner being slightly the longer. The tarsus of leg I 

 bears no scales, all the other segments of leg I bear one or more large 

 scales similar to those of the body. Tibia of leg I one and a half times 

 as long as the genual. Claws of the last three pairs of legs moderate, 

 situated on stout pedicels. 



Length, 0.32 mm.; breadth, 0.22 mm. 



Under a log. Collected by the writer at Urbana, 111. 

 Rhyncholophidae. 



Last segment of palpus transformed into a thumb, penultimate seg- 

 ment ending in a claw; mouth parts often retractile. Cephalothorax and 

 abdomen on the same plane with frequently no division between the 

 two; dorsal surface of cephalothorax with a long median groove which 

 usually ends in a tubercle at its anterior end. Eyes sessile, sometimes 

 six pairs present. 



This family is rich in species, most of which are found 

 in grass or upon the leaves of trees. 



Rhyncholophus Duges. 



Mouth parts not retractile; palpi of five segments; no eyes situated 

 on the anterior margin of the cephalothorax. 



Nine well-characterized species. 



KEY TO SPECIES. 



1. Body elongated and strongly constricted at the insertion of the hind 

 group of legs; setae of the body in the form of tridents 



R. tridentifer. 



Body shorter, if constricted at the insertion of the posterior group of 



legs, but slightly so; setae of body not forked 2. 



