326 
Psyche 
[December 
by man into Southwest Africa. Massonat (1909, Ann. 
Universite Lyon, N. S. CXXVIII, p. 248) mentions a speci- 
men of H. camelina collected off a horse in the Camargue, 
Southern France, the only record of the species, so far as 
I know, from the European shore of the Mediterranean. 
Hosts. — H. camelina is the specific parasite of the two- 
humped camel, Camelus bactrianus Linnseus, and of the one- 
humped dromedary, Camelus dromedarius Linnseus, which 
are now generally regarded as two domestic races of one 
single species. The ancestral form is found even now in 
the wild state in some of the deserts of Central Asia 
(Gobi, River Ob; western Mongolia). This wild ancestor 
had formerly a much wider distribution (see Keller, 1902). 
Affinities. — H. camelina is not closely allied to any 
other species of Hippobosca. The two pairs of vertical 
bristles and the complete abortion of the pulvilli are aber- 
rant features not found elsewhere in the genus. 
Rondani (1878) and Speiser (1902) have attempted to 
draw a specific distinction between the flies found on the 
camel and those from the dromedary, the supposed differ- 
ences being entirely based upon color characters. After 
examining many specimens from different localities, I 
have reached the same conclusion as Austen (1903), that 
these two forms cannot be separated even as varieties. 
In coloration H. camelina is very variable, even in a lot 
taken from the same host in one locality. The variation 
affects the markings of the thorax, as well as the color 
of the hair on the fronto-clypeus and at the tip of the 
abdomen. Moreover, since the camel and the dromedary 
are only races obtained in domestication from a common 
ancestor, one could hardly expect specific or sub-specific 
differences in their parasites. 
