400 CLASS INSECTA. 



three articulations, and the head does not advance above the 

 mouth. 



Sometimes the first articulation of the tarsi, as well as in 

 Colobicus, is very short, the following three are elongated, 

 entire, equal, and simply furnished with hairs underneath* 

 The palpi are thicker at their extremity. 



Thymalus, Latr., Peltes, Fab. Silpha, Lin, 



In the species whose body is almost hemispherical (Um- 

 batus), the knob of the antennae is proportionally shorter ; the 

 third articulation and the following are more attenuated than 

 the second ; the spurs of the legs are extremely small. 



Sometimes the first three articulations of the tarsi, at least 

 those of the males, are short, broad, emarginate, or bilobate; 

 the fourth is very small, little or not at all apparent ; the 

 maxillary palpi, at least, are filiform. 



In these, the limbs, or at least the anterior ones, are 

 widened at their extremity in the form of a reversed angle ; 

 the first articulation of the antennae is usually larger than 

 the secondj the elytra are generally truncated, or very obtuse 

 at the end. 



In the two following sub-genera the third articulation of 

 the antennae is sensibly longer than the following ; the knob 

 is formed abruptly, almost orbicular or ovaliform. 



I PS, Fab. Nitidula, Oliv. Latr. Silpha, Lin., 



Whose body is always oblong-oval, depressed, with the 

 posterior extremity of the abdomen uncovered. One of the 

 mandibles (the left) is as it were truncated and tridenticu- 

 lated at its extremity, and the other widened, and broadly 

 emarginated or concave at the same end. The terminal lobe 

 of the jaws is elongated. 



Some species of Fabricius seem proper to be referred to 

 his genus Engis. 



