1852.] 39 
B. Thorax stria marginali interiore nulla. 
+ Mesosternum truncatum; prosternum bistriatum. 
Prosternum striis para]lelis: (thorax stria exteriore nulla, corpus depressum) 12. 
Prosternum striis convergentibus: (thorax stria exteriore distincta vel nulla, 
corpus convexum) : . . : . : . . 13. 
tt Mesosternum emarginatum : prosternum estriatum. (Platysoma Leach. ) 
Prosternum postice planum, “(corpus depressum) : . 14. 
Prosternum postice compressum et marginatum, (corpus cylindricum) . 1d. 
The species found in the United States may be distributed as follows: 
1, corresponds to Omalodes Er.: the only United States is H. borealis (Omalo- 
des borealis Lec.) 
2, contains only H. planipes (Omalodes Harristi Lec.) ‘The name Harrisii 
being preoccupied for a species of group 6, must of course be changed. 
3, contains H. areuatus Say; binotatus Lec; lewvipes Er. and a new species 
allied to arcuatus. 
*5, is composed of a Californian species, H. 6-striatus Lec. (An. Lyc. 5.) 
6, contains H. interruptus Beauv. (obtwsatus Harris); merdarius Payk; im- 
munis Er; Harrisii Kirby; diversus Er. (stygiews Lec.); feedatus Lec.; cogna- 
tus Lec.; marginicollis Lec., and one new species. 
7, contains H. dispar Lec.; indistinctus Say; depurator Say; and one new 
species. 
8, H. spretus Lec.; curtatus Lec.; and two new species. 
9, H. civilis Lec.; cenosus Er. (deceisws Lec.); punctifer Payk; abbreviatus 
Fabr.; bifidus Say, and perhaps H. repletus Lec. which I have not examined; it 
is doubtful whether H. punctifer is really a native of our territory; the only one 
found may have been introduced. 
10, H. sedecimstriatus Say ; americanus Payk.; exaratus Lec. ; and two new 
species. 
11, contains only H. bimaculatus Linn. (obliqguus Say). 
12, H. venustus. Lec. and corticalis Lec. Small flat species having the ap- 
pearance of Platysoma; the posterior tibix are almost glabrous; H. venustus 
has the lobe of the prosternum shorter than any other species I have seen. 
13, H. subrotundus Er. and H.: vernus Say ; small convex species, one of which 
has an entire marginal stria on the thorax, the other none. A newspecies from 
Mexico has an abbreviated stria at the margin of the thorax. 
14, contains the small. flat species forming the genus Platysoma Leach as 
amended by Erichson, the posterior tibiz are more or less distinctly toothed. 
Our species are: H. carolinus Payk.; depressus Payk.; parallelus Say ; coarcta- 
tus (Platy. coarctatum Lec.); and a new specs 
15, Cylindrical species allied to the preceding; H. cylindricus Payk.; attenua- 
tus (Platy. attenuatum Lec.); gracilis (Pluges gracile Lec., P. cylindricum} 
Er., Hister frontalis|| Say.) 
C#ROSTERNUS. 
Caput deflexum, mandibulis retractis sed non obtectis, acutis. 
Antenrz sub frontis margine insertx, funiculo filiformi, capitulo triarticulato, 
ovali, compresso, apice subtruncato. 
Prosternum Jatum quadratum, utrinque truncatum; scrobiculi antennales angusti 
profundi ad angulum thoracis inferne siti. Tibiz antice compressa, sukdila- 
tatz, posteriores tenues glabra; tarsi posteriores non recepti. 
The body is globose, very convex; the abdomen perpendicularly deflexed at 
the tip: the funiculus of the antennz is filiform, the first joint longer and a little 
thicker than the others; the prosternum is very broad, truncate posteriorly, very 
slightly rounded anteriorly ; the cavities for the antenne are very deep, situated 
* Group 4 is oncded upon a curious nondescript Mexican species, H. costatus, in 
which the strie of the elytra are replaced by elevated ridges. 
