ART. 20. 



STUDIES OF THE BITING LICE — EWING. 



November 26, 1920, at the same place by A. Wetmore ; and one female 

 from skin of male Oryzomys^ species (Cat. No. 236273, U.S.N.M. 

 Biol. Surv. Collection) taken November 7, 1920, fifteen miles south 

 of Cape San Antonio, Province of Buenos Aires, Argentina, by A. 

 Wetmore. The last record is 

 probably that of a straggler. 



Gyropinae, new subfamily. 



Species going into the old 

 genus Gyroptis Nitzsch are so 

 diverse and widely distrib- 

 uted according to host species 

 that they should be placed 

 into several genera. Hence 

 this old genus is here split 

 into five genera, and there has 

 been added also a new genus 

 for a peculiar species which 

 has the anterior tarsi two- 

 clawed. 



The subfamily Gyropinde 

 is separated from the sub- 

 family Protogyrofhiae by the 

 characters already given in 

 the diagnosis of the latter 

 family. It is at once sepa- 

 rated from the other subfam- 

 ily to be here established by 

 always having the legs of the 

 second and usually having 

 the legs of the third pair, 

 each modified so as to form 

 a hair-clasping structure (fig. 1). This modification consists of an 

 elongation and transverse striation of the second segment of the 

 tarsus, which, together with the small terminal tarsal claw, forms a 

 large clawlike structure adapted for fitting into a "bootjack"" type 

 of tenaculum on the femur. This femoral tenaculum is formed by 

 a large divided tubercle at the base of the femur and is striate, or 

 furrowed, in the same manner as the second segment of the tarsus. 

 The Gyropinae are broad, stout lice and sometimes show a sexual 

 dimorphism. 



Contained genera. — Gyropus Nitzsch and five new genera to be 

 here erected. 



Fig. 



PUOTOGYROPUS NORMALIS. DOHSAL 

 MKW OF FEMALE, X 90. 



