42 Fleas of Eastern United States 



(Plate XXVIII, fig. 148) . Pronotum armed with a single row of 

 bristles and a ctenidium of about six spines on a side. Meso- and 

 metanotum and each abdominal tergite armed with a posterior 

 row of unusually long bristles anterior to which there may be 

 another row of much shorter bristles. Anterior tergites further 

 armed with one to four short stout dorsal teeth on a side. Three 

 antepygidial bristles present on a side of which the middle is 

 longest. Sternite VII without a sinus. Head of the receptaculum 

 seminis very large, about twice as long as wide, much longer 

 than the tail. For further details concerning the structure of 

 the female genitalia, see Plate XXVIII, fig. 149. 



Male. General structure essentially as in the female. Two of 

 the three antepygidial bristles aborted. Modified segments: 

 Sternite VII and posterior arm of sternite IX so close together 

 as to give the impression of two processes of a single structure. 

 The former with four spiniform bristles at the apex. Clasper 

 projecting above the dorsal margin of the abdomen, its process 

 hidden by the wide, diamond-shaped movable finger. Manu- 

 brium broad, ending in a curved point. Penis broad and ter- 

 minating bluntly; spring not long and not completing a turn. 

 For further details concerning the structure of the male geni- 

 talia, see Plate XXVIII, fig. 150. 



Records. IOWA — Luxemburg, November 13, 1937, two fe- 

 males; November 23, 1937, on Glaucomys volans volans (Lin- 

 naeus) , two females (T. Scott) . (UTAH— Salina, May 29, 1929, 

 on "Citellus 11101118," male.) 



Eastern hosts. Red Squirrel ("Sciurus hudsonicus") , Gray 

 Squirrel ("Sciurus carolinensis") , Flying Squirrel (Glaucomys 

 volans volans (Linnaeus) ) . 



Eastern localities. Illinois, Iowa, New York, (Utah) . 



Type material. Two males and two females from "Sciurus 

 hudsonicus" in addition to the holotype in the Collection of Dr. 

 M. A. Stewart. 



OPISOCROSTIS JORDAN 

 Opisocrostis Jordan, 1933, Nov. Zool., 39: 73. 



Genotype: Ceratophyllus hirsutus Baker 



Frontal tubercle prominent, extending beyond the anterior 

 margin of the head. Labial palpus reaching well beyond the 

 apex of the fore coxa. Bristles of the second antennal segment 

 very long. Pronotal ctenidium consisting of eight or nine spines 



