112 THE SERRICORNIA. 



various modifications, in all these beetles (with the 

 exception of the Brachelytrd) , since we quitted the 

 carnivorous Water Beetles. In this group these 

 organs are usually thread-like, or they taper gradually 

 towards the tip, and the joints are narrowed towards 

 the base in such a manner that the antennae com- 

 monly present the appearance of being notched on 

 one side like a saw, whence the name of SERRICOR- 

 NIA has been bestowed upon this tribe of Beetles. 

 It must be confessed, however, that they do not all 

 strictly fulfil the conditions necessary to justify this 

 name, and a few, not of the least curious, even pre- 

 sent a slight thickening of the terminal joints, which, 

 to say the least of it, gives a most unpleasant inde- 

 finiteness to the characters of the group. The majo- 

 rity, however, present peculiarities quite sufficient to 

 enable them to be easily distinguished from the mem- 

 bers of the other groups of Coleeptera, namely, a 

 simple external lobe to the maxillae, five-jointed tarsi, 

 filiform or serrated antennae of moderate length, and 

 ample elytra. 



Some of these insects exhibit a most curious con- 

 struction. They are of an elongated and somewhat 

 cylindrical form, tapering a little towards the hinder 

 extremity ; the head is deeply immersed in the pro- 

 thorax, which is usually rather long, and has its 

 hinder angles elongated in the form of spines, which, 

 resting against the shoulders of the elytra, prevent 

 any lateral movement of the fore part of the body. 

 When we examine the lower surface of this segment, 

 we find that the sternum is furnished with a stout 

 spine at its hinder extremity*, and that this is received 



* Hence the group of Beetles in question has received the 

 name of Sternoxia. 



