THe PsELAPHID2 OF NorTH AMERICA, 45 
shallower, with its discal lines short; the other three foveze 
are sharp and deep, the discal lines of the two middle ones 
nearly equal in length, reaching beyond the middle; sutural 
line deep, slightly arcuate, humeral tubercles strong, but not 
prominent. Addomen narrower than the elytra, border broad, 
arcuately convergent; first segment one-fourth as long as 
wide, depressed at the base in the middle third; the fourth 
segment (¢) similar at the base to the first, with two lunate 
depressions, which meet in the middle. Mesosternum (¢) 
deeply impressed, anterior coxe conical, contiguous, with a 
minute sharp tubercle on the exterior tip. Head punctured 
beneath, with a fine carina in the middle. 
Habitat. California. (Alameda County.) 
O. convexus, Casey. Form the same as in striatus. Length 
1.9 mm. 
Eyes their own length from the base. Antenne with the 
first and second joints cylindrical, last joint as long as the five 
preceding ones. Prothorax as wide as long, base two-thirds 
of the width, longitudinal sulcus very slightly dilated near the 
middle. Alytra with the two middle lines equal, two-thirds 
of the elytral length. 
Habitat. California. (Sonoma County.) 
O. ABBREVIATUS, Casey, differs from convexus by the base 
of the prothorax being three-fourths of the pronotal width, the 
longitudinal sulcus fine, not dilated. lytra with the middle 
lines unequal in length; the inner four-sevenths, the other three- 
sevenths of the elytral length. Length 1.9 mm. 
The difference between these two is very slight. In O. 
striatus the length of the elytral lines vary, and the pronotal 
longitudinal sulcus does not always end so abruptly anteriorly. 
Repeated examination of many specimens prove to us beyond 
doubt the identity of O. striatus, convexus and abbreviatus. 
O. MONTANUS, Casey. Form more slender, depressed. 
Length 1.8 mm. : 
The basal joints of the antenne are smaller than in the other 
