L. Harrison 
97 
Dinornithidae are closely related, it is not so improbable as it may seem 
at first sight that Aptericola was the type of Ischnoceran Mallophaga 
found upon the Dinornithidae. 
Finally I should like to discuss the Mallophagan parasites of the 
ostrich, rhea, and emu, to which, of living birds. Apteryx has hitherto 
been considered most closely related. I have already (1914, pp. 9-10) 
written something about the species found upon these three hosts. 
I have again looked into the matter carefully, and I am still of the 
opinion that these species, and their hosts with them, had common 
origin. In any case the Mallophaga of the larger ratite birds belong to 
a different family, and have no close relationship to the genus Rallicola. 
So the parasites of Apteryx differ radically from those of the remaining 
Ratitae, and are closely akin to those of the Rallidae. 
I have tried, in the preceding five paragraphs, to put an unpre¬ 
judiced statement of the case. The points I have wished to make in 
these paragraphs may be stated briefly as follows: 
(i) Aptericola is a normal parasite of Apteryx. 
(ii) Aptericola is certainly, at most, a sub-genus within the genus 
Rallicola. 
(iii) Rallicola is a universal parasite of rails, and of nothing but 
rails, except for the Parridae and Apterygidae. 
(iv) Aptericola possibly indicates the type of Ischnoceran parasite 
that existed upon the Dinornithidae. 
(v) The Mallophaga of the remaining Ratitae have nothing in 
common with those of Apteryx. 
The inference that I draw from these conclusions is that Apteryx 
(and possibly Dinornis also) is more closely akin to the Ralh than to 
any other living birds. Subsidiary deductions are that the Parridae 
are ralhne rather than limicoline; and that the Ralli are probably 
distinct enough to justify ordinal rank. 
Taking the latter first, though the position of the jacanas has been 
the subject of some discussion they are, in most recent classificatory 
schemes, definitely included amongst the Limicolae. This order has, 
however, the best limited groups of Mallophaga that we can point to. 
No person with any knowledge of the group could fail to determine at 
sight a parasite in any of the genera found upon limicolines, or, perhaps 
I had better say, upon the Charadriiform complex, as having come 
from a Charadriiform host. ('With this group, by the way, the parasites 
of the Pterocles and Columbae show no close affinity.) The Mallophaga 
of the jacanas do not fall within these well-marked limits. 
Parasitology vm 
7 
