1960] 
Christiansen — Genus Pseudosinella 
15 
Pseudosinella petterseni Borner 
Pseudosinella petterseni Borner 1901, Zool. Anz. 24: 707-8. 
Facies typical of genus. Color silvery white without trace of pig- 
ment. Head circular and eyeless. Antennae with fourth segment fusi- 
form, third segment truncately conical and remainder subcylindrical ; 
apex of fourth segment rounded ; apical organ of third segment with 
two subcylindrical pegs. Second thoracic segment not humped and 
the head prognathous at rest. Fourth abdominal segment about three 
and one half times as long as the third segment. Unguis with a small 
external tooth, and three well developed internal teeth; the basal pair 
not on a level and the basalmost one considerably larger than the re- 
mainder. Empodial appendage with a large outer wing tooth on a 
distinct lamella. Tenent hair strikingly clavate. Mucro with apical 
tooth twice as long as anteapical ; basal spine exceeding the apex of 
anteapical tooth. Anterior macrochaetae as follows: dorsum of head 
with a row of six setae along each antenna base, the setae in each row 
being alternately large and small, the posteriormost seta of each row 
is displaced inward; interantennal setae are concentrated near the an- 
terior margin of the head so that only two are clearly visible; ventral 
surface with scattered large setae on anterior one third of surface. 
Anterior margin of second thoracic segment with from two to four 
rows of setae. 
Type locality: epigeic, Frauenberg bei Marburg, Germany. 
Distribution: one of the commonest epigeic species in the United 
States; known in caves from Kendall and Burnett Counties, Texas, 
and Linn County, Iowa. 
Discussion 
The specimens seen from the Texas caves differ slightly from the 
epigeic forms seen in most of the country ; in the former the basal 
ungual tooth is smaller, the tenent hair clavate and the basal spine 
of the mucro shorter ; however, these variations are probably geograph- 
ical since epigeic specimens seen from New Mexico indicated similar 
modifications. Further collections from western caves will probably 
show this to be a much more common cave inhabitant than is presently 
indicated. 
Pseudosinella argentea Folsom 
Figures 31-37 
Pseudosinella argentea Folsom 1902, Psyche 9: 366. 
P (seudosinella) dccipiens (?) Bonet 1934, Arch. Zool. Exp. Gen. 
76: 370 - 3 . 
