On Fahrenholz´s purported new species subspecies and varieties of Pediculus

The object of this paper is to draw attention to certain grave sources of error underlying the present mode of differentiating Anoplura and more especially species of the sub-order Siphunculata. I am unable to say if the criticisms herewith advanced apply equally to the methods employed in differentiating members of the sub-order Mallophaga, because I am not familiar with the latter group, but the two sub-orders mentioned are in many respects so closely allied that it appears difficult to avoid the suspicion that the considerations herein contained may apply equally in both cases.