Packard.] ZOO [Sept. 2, 



"But the Mallopliaga were regarded by De Gear as a special group, and 

 by Nitzscli and others they were generally referred to the Orthoptera. 

 So far as I am aware, only Gerstaecker, in his "Handbuch der Zoologie," 

 places the Mallophaga at the end of the Hemiptera ; still he is inclined to 

 consider the group as a special one, forming a sort of transition from the 

 Hemiptera to the Orthoptera, but without forming a direct connecting 

 link. 



" Since until now, we knew only of the biting mouth-parts of the Mallo- 

 phaga, so the view that they were entitled to be regarded as Orthoptera 

 •was completely founded. In the Orthoptera we place those insects with 

 an incomplete metamorphosis and biting mouth-parts. But after the exist- 

 ence of a beak in the Mallophaga has been proved, it becomes evident that 

 they should be regarded as Hemiptera or bugs. 



"This conclusion is wholly indisputable when we recall the above men- 

 tioned similarity of the Mallophaga with the genuine lice. As to the 

 completeness of this similarity, I will call attention again to the relations 

 of the mouth parts, which have been cleared up by our embryological 

 studies. We are thereby brought to the conviction that in the lice as well 

 as in the Mallophaga, in their adult condition, no underlip (labium) exists, 

 while the mandibles and maxilla3 are present. The only difference in the 

 mouth-parts of the two groups is this : that in the Mallophaga these head- 

 appendages are the functional parts of the mouth-apparatus, while in the 

 Pediculidse they become rudimentary. 



"But such relative difierences do not have so great systematic value as 

 to lead us to place so nearly related animals in two different orders. 



"From the reasons we have presented we adopt the Linnean view that 

 the'Mallophaga belong with the Pediculidaj ; we think we are right in re- 

 garding both groups as families of the Rhynchota." 



From the foregoing facts and conclusions of Melnikow, we felt con- 

 vinced that he had demonstrated that the Mallophaga were Hemiptera and 

 nearly related to the Pediculidae. But after a, careful reading of Grosse's 

 memoir on the Mallophaga, translated by Prof. McCloskey, we think he 

 is right in considering that these biting lice are not genuine Hemiptera. 

 The very fact, admitted by Melnikow, that the mandibles and maxilife re- 

 tain their biting function and do not become rudimentary as in the Pedi- 

 culidse, and the fact pointed out by Grosse, that the second maxilhe do 

 exist in the Mallophaga, leads us to regard their louse-like shape as simply 

 adaptive, and that they belong to souie other group than the Hemiptera. 



If we examine Melnikow's excellent figures we see that after the mouth- 

 parts of the embryo of both the genuine Pediculidie and Mallophaga are 

 developed, the embryos of the two groups follow different developmental 

 paths. The large clypeal region of the Mallophaga becomes still larger 

 and broader, overhanging and concealing from above the labrum, which 

 is short and broad ; on the other hand, in the Pediculus it becomes long, 

 narrow and slender. The mandibles become true biting jaws, while in 

 the Pediculus they become long and slender ; the maxillae become minute 



