316 
Psyche 
[Vol. 91 
Scottiella Enderlein, Scytopsocopsis Lee and Thornton, Scytopso- 
cus Roesler, Trichocaecilius Badonnel, Trimerocaeeilius Mein- 
ander, Zelandopsocus Tillyard. 
It is likely that the adaptive zones of the three families are gener- 
ally distinct. The combination of absence of (or only minute) pre- 
apical denticles on the pretarsal claws, possession of broad pulvilli, 
and presence of ventral abdominal eversible vesicles in most Pseu- 
docaeciliidae probably signifies leaf dwelling, which is known for 
several of the genera. Presence of preapical denticles of the pretarsal 
claws, slender pulvilli, and absence of abdominal eversible vesicles 
in Philotarsidae may signify bark dwelling, as is the case in the 
Philotarsus and Aaronie/la species which I have observed. Some of 
these characters remain unrecorded for Bryopsocidae. The type spe- 
cies of this family has been taken most frequently on moss, suggest- 
ing a unique habitat for this group. 
The correlation of some of the characters to habitat noted in the 
above paragraph suggests the possibility of convergence between 
three-tarsal-segmented forms (Philotarsidae sensu Thornton, 1981) 
and two-tarsal-segmented forms (Pseudocaeciliidae sensu Lee and 
Thornton, 1967), but the hypothesis of phylogenetic affinity pro- 
posed here appears to be the simpler one and is supported by several 
characters which are not habitat-correlated. 
Can a sister-group relationship be seen among these families? In 
dealing with this question, one must note that Smithers (1967) pres- 
ented a very strong argument for close proximity of Family Pseudo- 
caeciliidae and Family Calopsocidae. This idea is not at all 
weakened by addition of Austropsocus and Zelandopsocus to 
Pseudocaeciliidae. Unless Calopsocidae, in which forewing venation 
has become complex and plastic, was derived from within the vena- 
tionally conservative Pseudocaeciliidae, these two families must 
have phylogenetic sister relationship. 
Judging from the extent of character sharing shown in Table 1, 
Bryopsocidae is probably the phylogenetic sister group of the com- 
mon stem of Pseudocaeciliidae and Calopsocidae. However, certain 
intriguing similarities occur in the wing, tarsal, and female genitalic 
characters of Calopsocidae and Archipsocidae which require further 
exploration. Secondary suppression of some of the Pseudocaeciliid 
characters may also have produced Family Trichopsocidae. 
