144 
Psyche 
[September 
the only species with which it might readily be confused is Lasio- 
trechus discus (F.), which also has eyes, wings, pubescent integument, 
and similar coloration. L. discus , however, has large, convex eyes, 
a strongly cordiform pronotum, an apical recurrent groove which is 
oblique to the suture, and most of the longitudinal striae vanish 
before reaching the apex. 
Key to Nearctic Genera of Trechinae 
i. Eyes pubescent; form elongate-subparallel, depressed; head 
with deep, sulcate frontal grooves extended backward 
onto sides of head; West Indies Perileptus Schaum 
Eyes glabrous or absent 2 
2(1). Form elongate-subparallel, depressed; head with deep, sul- 
cate frontal grooves extended backward onto sides of 
head; elytra with second longitudinal stria beginning 
at level of anterior discal puncture, third stria obsolete 
behind anterior discal; aedeagus with basal bulb open- 
ing between two lobes; color black or piceous; in North 
America known only from Panama to southern Mexico 
Cnides Motschulsky 
Elytral striation not as described; frontal grooves not sul- 
cate; basal bulb of aedeagus closed except for normal 
basal orifice 3 
3(2). Mandibles with a premolar tooth between retinaculum and 
and mola; color black, form Trechus-li ke, elytral discal 
punctures not on fifth stria; in North America, known 
only from Panama Trechisibus Motschulsky 
Mandibles without a disinct premolar tooth 4 
4(3). Elytra with anterior discal puncture on or near fifth stria 
OR if anterior discal puncture is absent, specimen micro- 
phthalmous, depigmented, from cave in Mexico 5 
Elytra with anterior discal puncture on or near third 
(rarely fourth) stria OR if anterior discal puncture 
absent, then specimen is not from cave in Mexico .... 6 
5(4). Color rufotestaceous ; eyes reduced to minute, pale areolae: 
form elongate, frontal grooves short, neck very narrow; 
inhabitants of caves in Mexico 
Mexaphaenops Bolivar 
Color black or piceous to pale piceous; eyes normal, or 
if reduced to pale areolae (Queretaro, Mexico), then 
frontal grooves normal, neck not very narrow; moun- 
