COLEOPTERA. 415 



ACROCINUS, Illig. 

 Distinguished from all the Longicornes, by the thorax, each side of which 

 is terminated by a movable tubercle, terminating* in a point, or by a spine. 

 The body is flattened, and the thorax transversal; the antennse are long and 

 slender, and the anterior legs longer than the others; the elytra are trun- 

 cated at the end and terminated by two teeth, the exterior of which is the 

 strongest. 



A. longimanus; known by the vulgar name of the Cayenne Harlequin. 

 The thighs and tibiae of the two anterior legs are very long and slender. 

 The movable tubercles of the thorax are terminated by a strong spine, and 

 the elytra are beautifully variegated with grey, red, and black. 



All the remaining Lamiaria compose but the single genus 



Lamia, 

 Which we will separate into two sections: those In which the sides of the 

 thorax are sometimes tuberculous or rugose and sometimes spinous, and 

 those in which it is smooth and cylindrical. 



They are arranged under various subgenera, such as Acanthocinus, Tetra- 

 opes, Monochamus, Saperda, &c. 



la the fourth and last tribe, that of the Lepturet^, we find Lon- 

 gicornes in which the eyes are rounded, entire, or scarcely emargi- 

 nated, and where, in this case, the antennae are inserted before, or 

 at most at the anterior extremity of this slight emargination. The 

 head is always inclined posteriorly behind the eyes in several, or 

 abruptly narrowed at its junction with the thorax, in the manner of 

 a neck; the thorax is conical or trapezoidal and narrowed before. 

 The elytra become gradually narrower. 



This tribe forms the genus 



Leptura, Lin., 

 With the exception of certain species which belong to the preceding tribes 

 and to the Donacise. In Leptura proper the head is abruptly narrowed 

 immediately behind the eyes. The antennae, inserted near the anterior 

 extremity of their internal emargination, are remote at base. The two emi- 

 nences from which they rise are almost confounded in one plane. The 

 thorax is almost always smooth or without lateral tubercles. 



