Horn.] 5 SO [April 19, 
epimera, so that while a specimen remains entire, the an- 
terior coxal cavities seem to be open. 
Two species are known in one fauna, one from each side 
of the continent and differing as follows: 
Thorax very little longer than wide, first abdominal segment punctured 
ci NGM soos [ode aoeoo omen bo olbne HGS COrOOL americanus. 
Thorax one third longer than wide, first abdominal segment very coarsely 
punctured over its entire surface...........-... .......Californicus. 
The latter species is much more closely allied to the European O. cwsus 
than the former. 
0. americanus Lec. New Species, 1863, p. 68. 
Elongate-cylindrical, ferruginous, shining, very sparsely clothed with 
semi-erect hairs. Head coarsely and deeply punctured. Thorax very little 
longer than wide, sides feebly arcuate, disc convex, coarsely and deeply 
but not densely punctured. Elytra scarcely wider than the thorax, disc 
with rows of moderately coarse punctures rather closely placed. Body he- 
neath coarsely and deeply punctured. Abdominal segments punctured 
along their margins, the first segment coarsely punctured between the 
cox. Length .10-.12 inch; 2.5-3 mm. 
Occurs in Pennsylvania, but rare. 
0. califormicus Crotch, Trans. Am. Ent. Soc. 1874, p. 75. 
Thorax one-third longer than wide, very coarsely and deeply punctured, 
median line smooth, on each side at base a deep linear impression extending 
one-balf to apex. Elytra feebly striate at base, and with rows of coarse, sub- 
quadrate punctures closely placed. Body beneath coarsely punctured. 
Length .12-.14 inch ; 3-3.5 mm. 
In all other respects this species agrees with the preceding. 
Occurs in Calaveras County, California. 
DERETAPHRUS Newn. 
Antenne at base free, received in deep, oblique grooves, eleven-jointed, 
last three forming a flattened mass truncate at tip. Head convex, deflexed, 
mouth inferior, in great part concealed by a prominent gular plate and 
the sides of the gene, mentum retracted. Anterior coxee moderately promi- 
nent, separated by a very narrow depressed sternum. Middle coxee moder- 
ately distant. Posterior cox oval, separated by a quadrangular process, 
oval at tip. Anterior tibis moderately dilated, the apical angle prolonged, 
the outer margin finely bidenticulate, and with two terminal spurs, the an- 
terior stouter and longer. Middle tibiz rather less dilated, outer edge mul- 
tidenticulate, two terminal spurs, the anterior longer. Posterior tibize simi- 
lar to the middle, outer edge simple. Tibiz within sparsely fimbriate. 
Tarsi moderately stout, first three joints gradually decreasing in length, 
fourth but little longer than the first. 
