16 
Psyche 
[March 
of body pale. Head. Labial appendage with external dif- 
ferentiated seta slender, acuminate, reaching only two- 
thirds of the distance from base of seta to apex of same 
papilla. Labral papillae rounded. Fourth segment with 
apical pit, but no retractile bulb. Legs. Smooth setae 
on third pair of legs slightly curved. Tenent hair with 
clavate tip very flat and thin. Unguis with three or four 
internal teeth, basal pair large, remainder small to minute. 
Lateral teeth very large, basal in position and reinforced 
by heavy ridges. Empodial appendage triangular, strongly 
Labral 
papillae 
o 
E 
LU 
/vyv\ 
V) 
3 
O 
-O 
2 
f\ r\pr-\ 
c, 
o» 
o 
x 
a> 
2 
A/y^A 
a 
c 
3 
o> 
o 
2 
Apex of 
antenna 
internal 
lamellae 
of unguis 
Text-figure 1. Representation of the condition of various organs in 
the species of Mesentotoma and in Entomobrya marginata. 
