i8 
Psyche 
[March - June 
arated on a basis of the cephalic chaetotaxy and the apex of the an- 
tenna. The variations of the unguis structure are most striking. 
Typically the median tooth is large, but it may be small (see figures) ; 
also the basal teeth are normally staggered and of different sizes, but 
they may be of equal size and/or at the same level. The external 
tooth is usually present but may be folded and virtually invisible. A 
small apical tooth may be present. The tenent hair varies from strik- 
ingly clavate to acuminate. Some forms are totally without pig- 
ment while others are clearly colored. The cephalic diagonal, fourth 
antennal segment and head also vary considerably in size. The an- 
tennal base setae also vary with size (as is normal for the genus) but 
the huge majority of specimens examined had the number noted. 
First examination of this material led to the belief that two or 
three species were involved ; but, with larger series of specimens from 
many localities and careful analysis of the variation, it became ap- 
parent that no clear boundaries could be drawn within the whole group 
and that the combinations of characteristics were virtually at random. 
It appears that some of the variation is geographic in nature (example: 
large median tooth more common in northern populations) but an 
analysis of this must await further and more complete collections. 
Specimens taken from caves in Virginia and identified by Bonet as 
P. decipiens (1934) are almost certainly argentea. It is quite possible 
that P. argentea is in fact synonymous with P . decipiens. The unguis 
in particular appears to have much the similar sort of variation in the 
European forms as in argentea. The figures for this species given by 
Denis, Bonet and Gisin would appear to indicate considerable varia- 
tion; however, there are certain striking differences. First, in argentea 
a common form has both teeth arising at the same level, and this ap- 
parently is never true with decipiens. Second, Denis indicates the api- 
cal organ of the third antennal segment in decipiens as consisting of 
two cylindrical, straight pegs, whereas in argentea they consist of two 
basically constricted, strongly curved elliptical pegs. The fourth an- 
tennal segment is relatively longer in argentea than Bonet indicates for 
decipiens, and the fourth abdominal segment is from four to five times 
as long as the third rather than 3 to 3.5 times longer as indicated by 
Bonet for decipiens. In view of all of these I feel it wiser to maintain 
argentea until such time as a careful comparative study can be made 
between this form and decipiens. 
Pseudosinella folsomi Denis 
Figures 22-24 
Pseudosinella folsomi Denis 1931, Mitt. Mus. Hamburg 44: 226-8. 
