THE FAUNA OF BOULDER COUNTY 253 



Family RHYNCHOLOPHID^ 



Mandibles styliform (for piercing). These mites are more slender and agile than 

 the Trombidiids. 



(103) Rhyncholophus Duges. An undetermined species occurs at Eldora. 



Order PSEUDOSCORPIONIDA 



The pseudoscorpions; small animals looking like scorpions, but without a tail. 



Family CHELIFERIDjE 

 Cephalothorax with a transverse median suture; abdominal scutes divided; 

 mandibles small. 



(104) Chelifer Geoffroy. Two distinct eyes; femur of palpus not pedicillate. 

 A new species (det. Banks) occurs at Boulder (W. P. Cockerell, February, 1907). 

 C. cancroides Linne has been found at Fort Collins. 



Chelanops grossus Banks is said to be quite common in Colorado; the genus 

 Chelanops has the femur of palpus distinctly pedicellate, suddenly enlarged near 

 base; palpi short and stout. Ideobismm tibiale Banks was described from material 

 collected by the writer at Florissant. This belongs to the family Obisiid^, in 

 which the cephalothorax has no transverse suture, and the abdominal scutes are 

 entire. Ideobisium has four eyes, and the mandibles have a stylet. 



Order PR A LAN GI DA 



The harvest-spiders, easily recognized in typical forms by the small, oval body 

 and very long legs; the abdomen is very broadly joined to the cephalothorax, 

 and there is a single pair of eyes. 



Family PHALANGIID^ 



With one simple (not compound) claw at the end of each tarsus, and with a claw 

 at end of palpus (Banks). Ours belong to the spinose tribe Phalangiini, the 

 Oligolophini of Banks. 



(105) Homolophus Banks. Femora wider than eye-tubercle; fifth joint of palpus 

 not longer than the third and fourth together (Banks). H. biceps (Thorell), Boulder 

 Canon, 7,340 ft., September, 1907 (Cockerell); determined by Banks. 



(106) Phalangium Linne. Fifth joint of palpus longer than the third and fourth 

 together; first femur longer than width of body. P. cinereiim Wood,* University 

 campus (Cockerell); det. Banks. 



Family COSMETID^ 



(107) Sclerobunus Banks. A forked claw on each hind tarsus. Our species red, 

 tips of legs black. S. robustus (Packard). Boulder Canon, 7,340 ft., September, 

 1907. 



Order ARAN EI DA 



The true spiders. Abdomen unsegmented, narrowly joined to the cephalothorax. 

 Several species were recorded from Boulder by Thorell in 1877; all those obtained 

 in recent years have been kindly determined by Mr. N. Banks, with the exception 

 of the Phurolithus. 



