PSYCHE. 



ARE THE MALLOPHAGA DEGENERATE PSOCIDS ? 



BY VERNON L. KELLOGG, STANFORD UNIVERSITY, CALIF. 



In a paper published in i8g6* I effect- 

 ively concealed some remarks which I 

 hoped might revive interest in a question 

 that of late years has been allowed to 

 drop into an undeserved innocuous de- 

 suetude. This question or problem con- 

 cerns the phyletic relations of those in- 

 sects which have been shuffled about by 

 systematic entomologists more perhaps 

 than any other insects, those namely that 

 began as a great host forming the order 

 Pseudo-Neuroptera. were later divided 

 into smaller hosts ordinally classified 

 as Pseudo-Neuroptera, Platyptera and 

 Corrodentia, and which now are wholly 

 freed from genealogical entanglements 

 with each other by appearing in the text- 

 books as a series of small orders, each 

 present order corresponding to the fam- 

 ilies of the earlier catch-all orders. That 

 my remarks had no attention was their 

 deserved fate ; deserved for allowing 

 themselves to get into a too corpulent 

 " new species " paper. Such papers are 

 properly filed for reference, not read, and 

 so my intention of giving the Psocidae 



*New M,illophaga II, from land birds, together with an 

 account of the Mallupliagous mouthparts. Conlrib. to liiol 

 from Hoplciiis Seaside Laboratory of Leland Stanford, Jr. 

 University, No, VII, 117 pp. 14 plates, November, 1S96. 



the ill name of being the ancestors or the 

 very immediate relatives of the ancestors 

 of the biting bird lice (Mallophaga) got 

 itself simply filed for reference. 



But I did mean to ask seriously the 

 question whether or not the Psocids 

 and the Mallophaga are not more nearly 

 related than their present classification 

 would lead one to suspect ; whether in- 

 deed they should not properly compose 

 a single order readily separable into two 

 sub-orders, but obviously linked by a 

 common descent. And in the last five 

 years I have, with the handling of many 

 more Mallophaga, and the occasional 

 re-examination of the Psocid body, had 

 my notions only made more distinct, and 

 my inclination to answer the question in 

 favor of the common origin of the two 

 groups only strengthened. And the 

 reasons for this believing are outlined in 

 the following paragraphs. 



While recognizing clearly the occur- 

 rence among unrelated forms of " paral- 

 lelism of development "and "parallelism 

 of structure " there is yet a certain de- 

 gree of similarity approaching identity, 

 whicli, when reached, we can explain 

 only on the basis of community of origin, 

 and descent. This degree of approxi- 



