STRUCTURES USED IN CLASSIFICATION. 



11 



The structure of the maxilla? has been much discussed 

 Scolytid literature, and the relation between the ra- 

 diating spines found on the maxilhe of bark-boring 

 Scolytids and the pilose lobes charaterislic of the 

 wood-boring Ambrosia beetles is of mucii interest. 

 These parts are however so small and difficult to ob- 

 serve that we have avoided using them in our kevs 



Fig S. Man- 



and refer the reader to the works of Hopkins, Swaine d ; b i e s of 



Rhynchites. 



and Nusslin for figures and further detail. (After Bedel.) 



The flexible palpi of Anthribidre and Rhinomacerinae have 

 already been mentioned. Our observation does 

 not entirely confirm the view conveyed by some 

 previous authors that these are entirely flexi- 

 ble, and we give therefore in Figs. 10 and 11 

 drawings of the beak of RhinniiKiccr showing 

 this type of palpus, certainly less rigid than 

 in other Rhvpchophora, but still preserving 

 the general character of the palpi observed 

 throughout the suborder. An illustration of 

 Fig. 9 . Ti P B of beak the head of Eupfu'ius iHfjubris, showing the 



of Balauiuus probos- 



ddcus showing vertical flexible palpi of the Aiithi'ibida? also appears 



mandibles. A, top 



view; B. side view. j n fi ie text treating of that family. 



(Original.) 



The mentum is used sparingly in the classification, being also 

 difficult to observe; but its differences and that of the buccal 



Fig. 10. Tip of beak of Rhinomacer from above. A, flexible palpi; B, horizontal 

 mandibles; C, antenna with loose, three-jointed club. Fig. n. Tip of beak of Rhino- 

 macer from beneath. A, flexible palpi. (Original.) 



cavity are of moment. The usual form has been shown in the 

 figure of the mouth parts of Pissodcs, where it is moderate in 

 size, not concealing the maxillre, and inserted upon a more or 

 less elongate gular peduncle. In Otiorhynchino* it is larger, 

 filling the buccal space and concealing the maxilla*. Interme- 

 diate forms occur in some genera like Kiloitti, Mo/tlius and 



