100 
Psyche 
[September 
C. caryae Bailey 2 
The average length of the first valve is 0.50 mm. 
and it varies from 0.46-0.53 mm. Valve two has a ridge 
present on the posterior margin of the common base con- 
necting the two valves. Variation in the length of these 
valves ranges from 0.40-0.44 mm. and the average length 
is 0.43 mm. Valve two is elongate. The subgenital plate 
is subcircular and is approximately twice as large as that 
of C. arcuata. 
C. ciliata (Say) 
This species exhibits the longest valves of any species 
studied. By comparing the length of each valve of this 
species with those of other species, C. ciliata can readily 
be separated from all others. The length of valve one 
ranges from 0.53-0.61 mm. and its average length is 0.58 
mm. The configuration of the ventral aspect of valve two 
affords a second excellent method of separating this species 
from all others (fig. 13). Its shape is extremely elongate 
and narrow compared to other species. The average length 
of valve two is 0.53 mm. and it varies from 0.50-0.56 mm. 
The subgenital plate is elliptical. 
C. coryli Osborn and Drake 
The average length of valve one is 0.46 mm. with 
variation occurring from 0.43-0.48 mm. Valve two is 
elongate with its anterior lateral angles pointed (fig. 15). 
Lengths of the latter valve vary from 0.42-0.43 mm. with 
an average length of 0.43 mm. The subgenital plate is 
elliptical. 
C. cydoniae (Fitch) 
The length of valve one varies from 0.36-0.43 mm. 
and its average length is 0.40 mm. The diagnostic character 
separating this species from all others is the convex shape 
of valve one (fig. 3). Valve two varies from 0.31-0.35 mm. 
and its average length is 0.33 mm. The shape of valve two 
is very diagnostic since it is unique (fig. 7). The subgenital 
plate is almost square with the posterior margin rounded. 
C. heidemanni Drake 
The length of valve one in this species varies from 
2 1951. The Tingoidea of New England and their Biology. Ent. Amer., 
31 n.s.: 1-140. 
