8 4 
Psyche 
[June 
smooth except for minute protuberance as shown in figure. Proster- 
num. Without subcondylic sclerotic lines. Pleuroprosternal sutures 
arching obliquely laterally, complete anteriorly. Anterior margin 
without diastema or denticle. Prehensors. When closed, not sur- 
passing anterior head margin. Trochanteroprefemur : basally bulging 
on inner side; without a denticle; outside length, 0.198 mm; inside 
length, 0.094 mm; basal width, 0.146 mm. Femoroid without den- 
ticle. Tibioid with a distinct but small denticle. Tarsungula: rela- 
tively short and robust ; basally with two large denticles ; dorsal edge 
smooth; ventral edge over proximal half dissected into about 4 coarse 
and rounded serrations; length, 0.208 mm. Poison calyx: of the simple 
type, consisting of bunched digitiform appendices; situated in femoroid. 
Poison gland situated entirely in the trochanteroprefemur. Tergites. 
Without evident paramedian grooves. Tergites and intertergites 
clothed with long, stiff, robust setae. Sternites. On the anterior 
third of body each with a midlongitudinal, shallow depression. Pore- 
fields: anterolaterals absent; each sternite from the first through the 
penult with two small, subcircular fields on extreme posterior margin. 
Pro- and metacoxal porefields present on the first through the penult 
pedal segments. Setae ; few in number ; arranged in regular horizontal 
rows. Legs. Clothed with stiff, long, robust setae. Pretarsi : very 
long and thin, curved ; parungues acicular, short, approximately equal 
in length. Ultimate pedal segment. Pretergite fused with its 
pleurites, i.e. without sutures or divisions bilaterally. Tergite: greatest 
width to length, 35 : 28 ; anterior corners rounded; sides straight and 
posteriorly convergent ; rear margin broadly rounded. Presternite 
with a vague midlongitudinal suture. Sternite with sides essentially 
straight and convergent, its rear margin weakly rounded. Coxopleuron : 
barely inflated ; ventrally with small, freely-opening, deeply-pigmented 
pores; 5 on each coxopleuron. Ultimate leg: greatly swollen, essential- 
ly tubular, notably much longer and more massive than the penults; 
tarsus consisting of two articles, the second about half as long as the 
first and conical in shape; pretarsus is a robust, dark claw; the whole 
leg clothed with robust, stiff setae; ventral and inner surfaces of all 
articles including and distal to the femur pierced by relatively large 
glandular pores. Postpedal segments. Gonopod distinctly bipartite, 
conical. Anal pores present and not concealed. 
To assist in locating Damothus within the growing complex of 
North American dignathodontid genera, I have presented a generic 
key here: it is the first to be published since that of Attems of 1947, 
p. 129. To some extent it had to be based upon information only 
