COLEOPTERA. 421 



They are peculiar to South America. 



In the fourth section of the Coleoptera, that of the THIMERA, 

 there are but three joints to all the tarsi. The Trimera form three 

 families. Those of the two first are closely related to the last of 

 the Tetramera. Their antennae, always composed of eleven joints, 

 terminate in a club formed by the three last, which is compressed 

 and in the form of a reversed cone or triangle. The first joint of 

 the tarsi is always very distinct; the penultimate is usually bilobate, 

 and the last, which presents a knot at base, is always terminated by 

 two hooks. The elytra entirely cover the abdomen and are not 

 truncated. 



FAMILY I. 



FUNGICOLJE. 



In our first family of this section we observe antennae longer than 

 the head and thorax united, an oval body, and a trapezoidal thorax. 

 The maxillary palpi are filiform or a little thicker at the end, but 

 are terminated by a very large and securiform joint. The penulti- 

 mate joint of the tarsi is always deeply bilobate. 



This family may be reduced to one great genus. 



ETJMORPHTJS, 



In the Eumorphi proper, the club of the antennae is abrupt, compact, 

 strongly compressed, and in the form of a reversed triangle. The maxil- 

 lary palpi are filiform, and the two last joints of the labials united form a 

 triangular club. 



They are all peculiar to America and the East Indies. 



FAMILY II. 



APHIDIPHAGI. 



This family consists mostly of Insects which have an almost hem- 

 ispherical body, A and a very short, transversal, and almost lunate 

 thorax. Their antennae terminate in a compressed and obconical 

 club, composed by the three last joints, and are shorter than the 

 thorax. The last joint of the maxillary palpi is very large and se- 



