RELATIONSHIPS AMONG PHILOTARSID AND 
PSEUDOCAECILIID GENERA AND A PROPOSED 
NEW FAMILY BRYOPSOCIDAE (PSOCOPTERA)* 
By Edward L. Mockford 
Department of Biological Sciences 
Illinois State University 
Normal, Illinois 61761 
Introduction 
In the classification of any group of organisms, views that have a 
long tradition are often difficult to put aside. We may weight certain 
characters heavily out of respect for such a traditional view. Weight- 
ing may even become an unconscious act if we uncritically include a 
particular character in the definition of a taxon. The character, 
then, comes to have absolute weight in our subsequent decisions 
about which subtaxa will be placed in the taxon and which will not. 
One must remember, however, that taxa, being constituted by organ- 
isms, have the capacity to evolve, and that any one character may 
have changed (evolved) in a subtaxon while others have not. We 
must not let a group definition come in the way of showing true 
relationships. 
There has generally either been implied or expressed the view that 
adults in the psocopteran family Philotarsidae have three tarso- 
meres (Pearman 1936, Badonnel 1951, Smithers 1972, Thornton 
1981). For some time, this was an indisputable fact, but Mockford 
and Evans (1976) and Mockford and Broadhead (1982), assigned 
species with two tarsomeres to this family. 
Various authors have noted that adults in the family Pseudocaeci- 
liidae have two tarsomeres (Pearman 1936, Badonnel 1951, Lee and 
Thornton 1967). This view remained unchanged until Meinander 
(1978) assigned a genus with three tarsomeres to this family. It 
appears now that adherence to the traditional view that Philotarsids 
should have three tarsomeres and Pseudocaeciliids should have two 
has led to a rather serious error in classification. 
* Manuscript received by the editor June 8, 1984 
309 
