Horn. | 592 [April 19, 1878. 
Two genera represent this family in our fauna which differ as follows : 
Antennal cavity visible from above ; prosternal lobe well marked concealing 
the parts of the mouth beneath ; metasternal side pieces concealed by 
Hie Conor e soo sana cuncduandadoc scat coud ........Murmidius. 
Antennal cavity opening in front, not visible from above ; prosternal lobe 
truncate ; metasternal side pieces with the sutures very evident...... 
; Mychocerus. 
MURMIDIUS Leach. 
The clypeus is broader before the insertion of the antenne and the labrum 
retracted. The antennal cavities are distinctly visible from above. The 
epipleure although narrow, cover completely the metasternal side pieces 
so that these are only visible at the posterior extremity (in the excavation 
for the leg) where they turn slightly inward to meet the coxe. 
M. owalis Beck, Beitr. bair. Faun. 1817, 1; Duval, Gen. Col. Eur., 
pl. 56, fig. 276. 
Ovate, convex, brownish, shining, sparsely clothed with an extremely 
fine pubescence. Thorax transverse, narrower in front, surface very finely 
punctulate and with a slight depression above the antennal cavity. Elytra 
with rows of distant punctures which become rapidly evanescent toward 
the apex and sides. Beneath very sparsely punctulate. Length .05 inch ; 
1.25 mm. 
This insect is very rare in our country and has probably 
been introduced. Specimens were given me by Mr. O. E. 
Janson, of London, England, who found them abundantly in 
some old straw. 
MYCHOCERUWS Erichs. 
Zimmerman, Trans. Am. Ent. Soce., 1869, p. 255. 
Labrum visible, parts of mouth visible from beneath, prosternal lobe short. 
Antennal cavity at the anterior angle of the thorax, not visible from above. 
Epipleure wider than in Murmidius, not covering the metasternal side 
pieces. 
So many of the characters have been given among the generalizations at 
the head of the family and by Zimmerman that it is not necessary to repeat 
them here. 
M. depressus Lec. (Murmidius) Proc. Acad. 1866, p. 376; Zimm. loc. 
cit. 
Broadly oval, depressed, ferruginous brown, sparsely pubescent. Thorax 
transverse, sparsely punctulate, sides moderately arcuate and narrow in 
front, base slightly narrower than the elytra. Elytra with rows of moder- 
ately coarse punctures which gradually become feebler toward the sides 
and tip. Body beneath very sparsely punctate. Length .04 inch; 1 mm, 
This.species occurs from District of Columbia to South 
Carolina, and very rare. 
