gmCGERS — FARRELL 203 



AW 65-99, mean 78.9; PW 85-121, mean 101.7; AP 17-21, mean 19; 



SB 28-47, mean 36.4; ASB 25-37, mean 30.6; PSB 9-11, mean 10.1; 



AL 32-41, mean 37.3; AM 35-42, mean 38.4; PL 57-66, mean 60.6; 



S 32-38, mean 35.3. Width of sensilla of four specimens, 14 to 16, 



mean 15. 

 Eyes: Two pairs; anteriors lateral to posterolateral setae. 

 No ocular plate, although there is some appearance of one in 

 unengorged specimens. Measurements from five specimens: 

 Diameter of anterior eyes, 11 to 13, mean 12.2; of posterior eyes, 

 8 to 11, mean 9.8. 



Dorsal setae: Similar in form to the anterior dorsal setae of 

 E. okioensis but with somewhat less disproportion in size of the 

 two kinds of setules. A strong tendency for extra setae in the 

 rows. Measurements for eight specimens: Length of humerals, 

 57 to 63 ; of setae near the middle of the first posthumeral row, 

 51 to 61 ; of posterior setae, 38 to 46. 

 Dorsal formulae for seven specimens from Pennsylvania: 



2 (type) 



Ventral setae : Poststernals with numerous setules. Data from 

 eight specimens : Number of first sternals, 2 ; of second sternals, 

 2 ; of poststernals, 54 to 68. Length of first sternals, 47 to 55 ; of 

 second sternals, 39 to 50; of setae near the middle of the first 

 poststernal row, 32 to 35 ; of setae in the posterior group, 44 to 49. 



Material: Type, USNM 1998. Specimens from hosts, all from 

 Pennsylvania : 



Clethrionomys gapperi 



Wayne County: July 9, 1945, KU-1. 

 Clethrionomys gapperi paludicola 

 Venango County: Apr, 18, 1947, 

 CM-1. 

 Peromysciis leucopus novehorac^nsis 

 Mercer County: July 11, 1947, 



DU-1. 

 Blair County: June 8, 1949, DU-1. 

 Peromyscus sp. 

 Venango County: Jan. 20, 1948, 

 USNM-1, CM-1. 



Bradford County: Oct. 30, 1949, 

 DU-1, RMI^2. 

 Pei'or/iyscus vianiculahis 



Venango County: Jan. 23, 1948, 

 DU-1. 

 Peromyscus leucopus 



Blair County: June 26 or 27, 1949, 

 USNM-type+2, DU-3, CEF-2, 

 A'^s-1, Afr-1. 

 Clethrionomys sp. 



Bradford County: Nov. 11, 1949, 

 CEF-1; Nov. 13, 1949, CEF-1. 



Seasonal distribution: E. crateris has been collected in all 

 seasons. 



