120 THE ORDER OF COLEOPTERA. 



length. Their colors are black or brown, and some of those of the lat- 

 ter color are ornamented with yellow markings. 

 The following are the principal genera : 



A. Head without a neck. 



B. Antenna? with the four last joints abruptly enlarged '. Tetratoma. 



B B. Antenna; filiform or slightly and gradually enlarged. 

 C. Anterior coxte contiguous. 



D. Middle coxa) contiguous, with distinct trochantins Mei.andkya. 



DD. Middle coxa? separate, without trochantins Sekropaltus. 



C. Anterior coxa,' separate. 



E. Head horizontal : Stnchkoa . 



E E. Head vertical EusTROi'iius, Hai.lomenus, Orchesia. 



A A. Head with a short neck ; eyes coarsely granulated and deeply notched Scraptia. 



We have space to refer to only a few of the most noticeable species. 

 We have two species of Tetratoma, which depart from the ordinary 

 habits of the family by being inhabitants of fungi. The Melandrya^ 

 striata, Say, is six-tenths of an inch long, pure black, the thorax with a 

 middle furrow, and a depression on each side, and the elytra deeply 

 striate and punctate. Serropalpus 4:-maculatus, Say, is a third of an 

 inch in length, of a deep brown color, with two angular yellow spots on 

 each elytron. Hypnlus trifasciatnsj Melsh, is quarter of an inch or less 

 in length, yellow, with three irregular brown bauds across the elytron. 

 These, like the other species of the family^, are found under the loose 

 bark of trees in an advanced state of decay. One of the most common 

 larv;e found in such situations is that of the SyiicJiroa punctata, Newm., 

 a plain light-brown species about half an inch in length. This larva is 

 of an elongate cylindrical form, with six short legs, and two horny 

 l)oiiit8 at the posterior extremity of the body. 



The genus Penthe, of Newman, is placed in this family by LeConte, 

 but in the sub-family of Helopides by Lacordaire. The palpi are rather 

 long and robust, but not hatchet-shaped at the end like most of the 

 Serropalpi. It contains two rather large, oval, depressed beetles, up- 

 wards of half an inch in length, and of a deep black color : the P. ohll- 

 quota, and the P. pimelia, of Fabricius ; the former being distinguished 

 by having the scutelluin clothed with rustred hairs. They are common 

 species, being found under the bark of decayed trees and in rotten 

 stumps. Their sub-cortical habits furnish an argument for retaining 

 them in the present tribe. 



Tribe XIV. 

 nETEROMEROUS GROUND-BEETLES. 

 Heteromera terricola. Melasoma, Latreille. 



This tribe contains a large and diverse assemblage of beetles, distin- 

 guished chiefly by their heteromerous tarsi, their usually slightly cla- 



