Some Ectoparasites in the South African Museum. 279 



have reported on collections made in certain regions of the conti- 

 nent. Any necessary references are given tinder the species treated 

 in the following pages. It has not seemed advisable to attempt to 

 offer a complete Bibliography. 



As the genitalia 3 have been referred to frequently, the descriptive 



terms used may be briefly explained. The sexual apparatus of the 



$ in what we believe to be its primitive Philopterid form consists 



of 9 parts in two regions. These are illustrated in the figures of 



N. opacus and N. macrocephalus. (PI. XXV., figs. 2-4.) 



1. There is a broad laterally thickened chitinized lamina, which is 

 wholly internal and to which numerous strong muscles are attached. 



2. Externally there are 6 parts placed symmetrically about the 

 tubular penis and one additional below. This last is often hard to 

 make out, and may look like a swollen base to the penis. The penis, 

 however, seems to take constantly the form of a simple tube. Snod- 

 grass (1899) has already figured and described several examples of 

 this type, and Mjoberg (1910) refers constantly to the genitalia. 

 But it has not yet been sufficiently grasped that the apparatus gives 

 by far the best characters for the discrimination of species. Snod- 

 grass calls the portion inside the abdomen the "internal plate"; 

 Mjoberg speaks of the "basal plate," a name we personally prefer. 

 To the distal end of the plate at each side, and articulating distinctly 

 with the plate, are two broad curved chitinous blades provided with 

 a sub-terminal outwardly directed lateral hair and one median or 

 post-median ventral hair. These "blades" Mjoberg calls " para- 

 mera." The paramera can move freely upwards, and may be 

 completely reversed to lie parallel with tergites 7-9. They can 

 also move scissor-like towards one another. As no names appear to 

 have been given to the parts within the area circumscribed by the 

 paramera, we propose the following : 



(a) Endomera for the two appendages lying next the paramera. 

 The endomera are feebly movable distally from one another, but are 

 fused proximally. The paramera articulate both with the endomera 

 and the basal plate. The endomera bear, generally medianly or post- 

 rnedianly and sometimes laterally, ventral hairs whose position may 

 have specific value. 



(b) Appearing inside the endomera and at either side of the penis 

 are two smaller telomera. They are best seen in those species where 

 they project far beyond the endomera. 



(c) The hypomeron is the unpaired process beneath the penis. 

 (r7) The endomera are above the penis. The telomera alongside 



and above the penis and the hypomeron below. All five parts may be 



