CHIGGERS — FARRELL 137 



mined by comparing specimens with drawings. A set of drawings 

 of the legs of E. miricoxa was obtained from the Rocky Mountain 

 Laboratory. The form of the segments and the form and arrange- 

 ment of the striated setae are typical of E. pipistrellL The lo- 

 cality from which E. miricoxa was taken falls within the range 

 of E. pipistrelli (fig. 4,c) . A consideration of the standard data 

 of the type series, of specimens from east of the Mississippi 

 River, and of E. miricoxa does indicate that there is generally a 

 smaller AP measurement for the eastern specimens. The average 

 of 10 AP measurements from the type series, which is western, 

 is 24 (Brennan, 1947). The AP measurement of E. miricoxa is 

 17 (Brennan, 1948) . The AP measurements of 13 eastern speci- 

 mens include these extremes, but the mean is 20. There is some 

 possibility of subspeciation, but further collections and study are 

 required for proper evaluation. The two species are here con- 

 sidered to be the same and E. miricoxa to be a synonym of E. 

 pipistrelli. 



6. Euschdngastia oregonensis (Ewing) 



Figures 1, 2, 3, 4,a; Plates 6, 11 

 Tromhicula oregonensis Ewing, 1929a, p. 11; 1931, p. 9; 1942, p. 488. — 



Radford, 1942, p. 57.— Michener, 1946, p. 432.— Sig Thor and Willmann, 



1947, pp. 260, 286. 

 Euschdngastia oregonensis, Fuller, 1948, p. 106; 1952, pp. 182-183, 184. 



Description : Size : Engorged length, 505 to 535 ; width, 385 to 

 410. 



Shape : Broad oval. 



Gnathosoma: Rather small feathered seta on palpal femur. 

 Seta on genu smaller, with few setules. Dorsal seta on palpal 

 tibia longer with a few setules on its outer curvature; lateral seta 

 with one to three setules ; ventral seta with relatively few setules. 

 Palpal claw curved with five prongs, median longest, two 

 slightly shorter, and two shortest on the outer curvature. Galeal 

 seta with one to three setules. Chelicera typical ; subapical dorsal 

 and ventral teeth distinct. Palpal coxa and femur and base of 

 chelicera punctate. 



Legs : Leg I with two typical genualae of moderate length and 

 one microgenuala ; two tibialae normally placed, the more proxi- 

 mal tibiala longer, and a microtibiala slightly posterior to the 

 distal tibiala ; strong spur on the middorsal surface of the tarsus 

 with microspur about half the length of the spur distal and 

 slightly posterior; subterminala, parasubterminala, and pretar- 

 sala typical. Leg II with one typical genuala, two tibialae in 

 tandem, a strong spur with proximal microspur, and a pretarsala. 

 Leg III with single, typical genuala and tibiala. Setules mostly 



