LAND SCAVENGER-BEETLES. 
59 
The following are the three typical genera : 
A. llead perfected ; mandibles as long as the head ; body very flat ; size comparatively large— 
IlOLOLEPTA. 
A A. Hoad retracted ; mandibles short ; body usually convex, (flattened in sub-genus Paromalus.) 
B. Prosternum advanced so that the head is invisible from beneath Hjstek. 
B B. Prosternum not advanced Sai'IUNUS. 
Ulster is divided by Dr. LeOonte into ten lesser genera, which De 
Marseul has still further subdivided so as to form four additional ones. 
These divisions are made in accordance with slight organic variations, 
which however are sometimes accompanied by differences in size, or by 
perceptible modifications of the general form. 
More recently, Dr. Geo. H. Horn has contributed to the American 
Philosophical Society (June, 1873,) a valuable synopsis of the Histerkhe 
of the United States, in which all our species are carefully reviewed 
and described. 
Family X. NITIDULIDiE. 
The typical insects of this family constitute the genus Nitidula of 
Fabricius, a word literally meaning shining, or elegant, but which is sin- 
[Eig. 21 .] gularly inapplicable to the insects of this family, as now 
constituted, most of which are clothed with a line pube- 
v w scence, which is incompatible with a shining surface. They 
are small, somewhat flattened beetles, the thorax having a 
.wide, thin margin, and the wing-cases more or less cut off 
nitidui.a i. behind, so as to leave the end of the abdomen exposed. In 
susTs’aiiten- the sub-family .of Carpophilides, the elytra are so short as 
Westwood. 8 ‘ to leave two or three of the' abdominal segments uncovered, 
but in the Nitidulides only the tip of the abdomen is exposed. The 
fourth tarsal joint is very small, and wholly wanting in the hind tarsi 
of the males of some species. Their colors are usually brown or black- 
ish, with or without dull yellow spots. 
The insects of this family vary much in their habits. Some are found 
on carrion and others on flowers ; several of the most common species 
are often met with on apples and other fruit in a state of decay. The 
larvae of the genera Ips Carpophilus and Rliiozopliagus, have been 
shown by the observations of a French author, M. Ed. Perris, to be car- 
nivorous, subsisting upon soft, sub-cortical larvae. 
Ninety N. A. species have been described, under the following prin- 
cipal genera : 
A. Antenme 11 -jointed, club 3-jointed ; body oval. 
B. Only the tip of the abdomen exposed. 
C. Surface pubescent ; colors dull ; upper lip exposed. 
D. Body depressed ; thorax not overlapping the elytra ; color brown, usually with obscure yel- 
low spots Nitidula. 
D D. Body convex; thorax slightly overlapping the base of elytra. Color brown, usually shaded 
with black •. Cychkamus. 
0 C. Surface smooth and shining; color black, spotted with yellow or reddish ; htf>rum concealed : 
Ira. 
B B. Two or threo last segments of abdomen uncovered by elytra Carpophilus. 
A A. Autennaj 10-joiuted; club solid; body elongated Ruizophagus. 
