STUUI 'TURKS USED IX CLASSIFICATION. 



9 



It should be understood that the mouth parts are often so 

 concealed in the apex of the beak that dissection as well as mag- 

 nification are necessary for inspection. 



In the figures that precede, it will be noted that there is a 

 single median gular suture and that the palpi are short, rigid, 

 and conical, the joints successively diminishing in size. We in- 

 troduce at this point a figure of the head of PterosticJiiis for the 

 purpose of showing thereby the pair of sutures which limit the 

 gu!a in the Coleoptera genuina and also the flexible character of 



Fig. 4. Pterosticluis californicus. A, lower view of head; B, upper view of head. 



(After Hopkins.) 



the palpi. These are the constant characters which separate the 

 Ehynchophora from the other Coleoptera, which were treated in 

 the "Coleoptera of Indiana." There is no exception to the gular 

 suture character known to us, and but few to the palpi ; these 

 are, however, less rigid in the familv Anthribidse and subfamily 



o - 



Rhinomacerinse, which therefore occupy a relatively low rank and 

 approach more nearly the normal Coleoptera. 



The most obvious character of the Rhynchophora, the one to 

 which they owe their common name of snout beetles, is the beak 

 or rostrum. It is very variable in development, and often even 

 absent. A somewhat medium form was shown in Fig 1. An 

 extreme development is seen in the genus Balaninus, figured later 

 on, while in Dciulroctonitx and other Scolytida- il is extremely 

 short or wanting. 



