284 Annals of the South African Museum. 



NIRMUS MACROCEPHALUS, spec. nov. (PI. XXV., figs. 2 and 5.) 



10 $ $ , 14 $ $ . Aegialitis pccuaria. 



7 $ $ , 8 $ ? . Aegialitis tricollaris. Sept., 1913. 



13 J c^ , 8 ? ? . Aegtaiitis marginata. Sept., 1913. 



This is a very characteristic Nirmus of the bicuspis, N., type. 

 [Giebel, Ins. Bpiz. p. 155, pi. v. figs. 11, 12 (1874).] We do not 

 give a detailed description of the chaetotaxy, since such differences 

 as we have noted between the South African insect and N. 

 hiaticulae, D. [Monogr. Anopl. Brit. p. 136, pi. xi. f. 10 (1842)], 

 (which we take to be bicuspis, N.), and N . opacus, Kell. and Chap. 

 [New Mallophaga, iii. p. 83, pi. vi. fig. 6 (1899)] , are probably 

 immaterial. We have hiaticulae from Britain, and Professor Kellogg 

 has very generously presented for dissection one of the three extant 



$ <$ Of OTjaCUS. 



The chief distinguishing feature externally is the long head, which 

 is also extremely narrow, viz. $ length -4 mm., breadth -27 mm. 

 (opacus - 4 and -31). In macrocephalus the signature is short and 

 broad, in opacus more elongated with a backwardly produced apex. 

 Length macrocephalus g, 1*35 mm.; opacus $ , I'll mm. 



The genitalia of macrocephalus are distinct. The basal plate is 

 posteriorly (as it lies in the insect "anteriorly") expanded. The 

 paramera are evenly curved almost their whole length, and bear the 

 ventral hair far forward, apically the paramera contract rather sud- 

 denly. The rneosorne is long with parallel sides. The V-shaped 

 ventral pattern extends to the articulation of the paramera with the 

 basal plate. Each endomer is slightly contracted near the apex, 

 where there are in side-view one or two rugose papillae which may 

 bear minute sensory hairs. Ventrally 3 or 4 hairs on each endomer. 

 The penis with the telomers distinctly fails to reach the level of the 

 endomers. In hiaticulae, D., and opacus, Kell. and Chap., the basal 

 plate is small and narrowed posteriorly. The paramera bend more 

 abruptly than in macrocephalus, and at a greater distance from the 

 apex. The ventral hair is thus placed not so far forward. The 

 paramera are considerably narrowed on the apical third in both 

 forms, but they are more slender near the basal plate in opacus 

 than in hiaticulae. In both the penis, the endomers, and the 

 telomers reach the same level. The penis is thicker than in the 

 form described. The sides of the mesosome are in opacus curved 

 from base to apex, in hiaticulae sub-parallel for the greater part 

 of their lenth. The minute hairs are also more numerous in 





opacus than in hiaticulae. All three forms are close to one another, 



