Xii INTRODUCTION. 



The rostrum is usuall}' marked on each side by a more or less 

 deep groove, which varies in length from a mere fovea to a long- 

 groove which gives lodgment in repose to the first joint of the 

 antennae ; they are called scrobes. 



The upper surface of the head is divided into regions, the back 

 part being called the occiput, the middle the vertex, and the 

 anterior portion i\\e front; on each side of the head are the eyes. 



The eyes of Coleoptera are very variable in form and shape, 

 and iire composed of aggregated small lenses ; rarely they are 

 entirely w^anting; equally rarely accessory eyes are seen in the 

 form of one or two simple lenses ; they are situated between the 

 compound eyes, on the posterior part of the vertex, and are called 

 ocelli. 



' In the Cicindelidse and Carabidag, in addition to the ordinary 

 pubescence, the head bears moderately long erect sette arising 

 from special punctures situated above and usuallj-close to the 

 eyes; from their position they are called supra-orbital setse, and 

 have been used as a means of subdividing the Harpalinfe. 



The under surface of the head in front is variably excavated, 

 forming the mouth; the parts beneath the eyes and behind the 

 mandibles, forming the lateral boundary of the mouth, are called 

 the genix ; behind the mouth the region is called the throat or 

 gula; the suture between the mentum and gula is called the 

 mental .•odurc; when the gular region is more or less prolonged 

 at middle for the support of the mentum, this portion is called 

 the sub-mental peduncle; from the opening of the mouth two 

 sutur(!s may usually be observed running Backwards; these often 

 coalesce at middle, but separate at each extremity; these are 

 called the gular sxdures. In the sub-order Rhynchophora there 

 is but a single suture, the lateral membei's of the head having 

 a.j)parently coalesced at middle without any true gular piece be- 

 tween them. 



Antenna. — The antennae are articulated appendages which 

 vary in form, insertion, and the number of joints. In the first 

 or normal series of Coleoptera they are inserted in front of and 

 more rarely between the eyes — usually under the side margin of 

 the front. In the Rhynchophora the antennae arise from some 

 portion of the rostrum in any position from the margin of the 

 eye to the tip of the beak. The number of joints varies, attaining 



