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. Anteunte with the four last joints abruptly enlarged Tetratoma. 



B B. AntenniB iiliform or slightly and gradually enlarged. 

 C. Anterior coxae contiguous. 



D. Middle coxa> contiguous, witK distinct trochantins Melandrta. 



DD. Middle coxjB separate, without trochantins SEKUOPALrus. 



C C. Anterior coxfe separate. 



E. Head horizontal Synchroa. 



E E. Head vertical EusTRorH us, Hallomenus, Orche8Ia. 



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 4c-maculatus. Say, is a third of an 

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

 each elytron. Hypulus trifasciatus, Melsh, is quarter of an inch or less 

 in lengtli, yellow, with three irregular brown bands 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 

 larvte found in such situations is that of the Synchroa 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 

 points 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. ohli- 

 quata, and the P. pimelia, of Fabricius ; the former beiug distinguished 

 by having the scutellum clothed with rust-red 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. 



HETEEOMEROUS 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 da- 



