678 MR. B. F. CUMMTNGS ON LICE 



I am able to describe the male copnlatory apparatus from a 

 j)reparation kindly lent me by Mr. Waterston. This belongs to 

 much the snme type as that in P. humeralis. 



Male Copulatory Apparatus. — Basal plate : The characteristic 

 feature is its small width in proportion to the dimensions of 

 the paramei-es and mesosome, which are attached to it. Basal 

 transverse band very convex. Parameres: Large powerful rods, 

 with lai-ge circular condyles working over the tiny articular 

 surface offered by the posterior lateral angles of the basal plate. 

 Distally they bend in somewJiat towards one another. Subapically 

 a minute hair. Mesosome : There are two endomeres, a lower and 

 an upper, the former being a small deeply bifid plate, each limb 

 of the fork running out behind into an attenuated tip. The 

 upper endomere has two wings, narrower at the distal end than 

 in P. humeralis, and here solely consisting of the lateral tooth 

 or notch pointing outwards. The j^enis is a delicate rod with a 

 large bulbous base (hypomere) ; above lie the " winged" telomeres, 

 which together look like a javelin's head. 



A comparison between text-figures 22, 23 & 24 clearly indicates 

 the homologies between the parts in the three species. 



Family Lipeurid^. 



The Lipeuri of Stkuthious Birds. 



Degee7'iella asymmetrica N. is found on the Emu {Dromceus 

 novce-hollandice (Lath.)), Lipeurtis asymmetricus P. on two species 

 of Rhea (Pterocnemia pennata (D'Orb.) and Rhea macrorhynclia 

 Scl.), Lijjeurus quadrimaculatus P. on Struthio camelus Linn, and 

 Rhea americana, Lipeurus latits P. on R. americana. There can be 

 but little doubt that these four species are related to one another 

 and should be grouped together. Subsequent research and the 

 rediscovery of Piaget's L. latus M'ill probably result in the 

 establishment of three new genei-a placed together in a new 

 subfamily. 



Harrison (22) has already suggested that D. asymmetrica, 

 L. asyvimetriciis, and L. quadrimaculattis should be regarded as 

 congeneric. From the new genus established below to include 

 L. asymmetricus and L. quadrimacidatus, I have omitted D. asym- 

 metrica, as in my opinion it should stand in a genus by itself. It 

 is a curious and significant fact that in three of these species 

 parasitising Struthious birds the margin of the anterior part of 

 the head is from some cause by no means evident asj^m metrically 

 developed. The asymmetry in the anterior incrassation of the 

 head is least developed in L. quadrimacidatus, while in the larva 

 of this species, as well as in the larva of L. asymmetricus, the 

 asymmetry is absent even in Stage TI. That D. asymmetrica, in 

 which the adult asymmetry is most developed, the w^hole of the 



