Some Ectoparasites in the South African Museum. 281 



while on Vanellus there is a larger race for which temporalis, G., may 

 meantime be retained. We have looked hitherto in vain for structural 

 differences, but we have not yet had an opportunity of dissecting 

 var. temporalis. We have, in fact, seen but one adult $ of this form. 

 The problem of separating the races of cordiceps is complicated not 

 merely by the evident fineness of the distinctions (if they really 

 exist) but also by the sociable nature of the hosts, which facilitates 

 transmission of the parasites in a confusing way. 



DOCOPHORUS CURSOR, N. 



D. cursor, Nitzsch, in Giebel, Ins. Epiz. p. 75, pi. x. figs. 5, 6 



(1874). 



3 $ 3 , 3 ? 2 . Bubo capensis. 



15 $ $ , 14 $ $ , 10 imm. Bubo maculosus (Spotted Eagle Owl). 

 Philipstown, C.P. 



With regard to the Docophori of the owls, we find ourselves at 

 present in substantial agreement with the position taken up by 

 Professor Kellogg in a suggestive short paper in Science, N.S. vol. 

 xxxvii. No. 943, p. 154 (1913). We have seen Docophori from about 

 a dozen species of owl from various localities Canada, Iceland ?, 

 Great Britain, East Prussia, and South Africa and think with 

 Kellogg that three types celebrachys, N., cursor, N., and rostratus, 

 N. will cover most of the species (about a dozen) hitherto reported 

 from owls. This at least should be a satisfactory position to adopt 

 until the $ genitalia have been compared. 



The case of the owl Docophori is, however, but a special instance 

 of a condition occurring frequently among the Mallophaga, viz. the 

 attachment of what seems, superficially at least, the same species (or 

 group of species) to similar hosts (i.e. of the same or allied genera) 

 over a wide geographical area. It should be insisted upon that each 

 series of parasites is to be discussed on its merits. The genus Doco- 

 phorus seems little given to variation other than in size and colour ; 

 but Nirmus and Lipeurus are full of surprises. It would be hard to 

 say, e.g., how many absolutely distinct species are at present confused 

 under the name N. furuus, N. The ? 5 offer such slight differences 

 that one would never imagine they were of specific value apart from 

 the confirmatory evidence supplied by the other sex. The $ $ too 

 are very similar, but by the genitalia are sharply separated from one 

 another. We are, of course, here at the margin of a wide question, 

 viz. what characters are to be regarded as specific in the group 

 Mallophaga. We only wish to state our opinion that while similar 



