362 Dr. F. Meinert on the Campodeie, 



sects, it has been attempted by several authors to maintain the 

 subdivision of the whole class (first indicated by him) into 

 Mandibtdata (Masticatores) and Haustellata (Suctores), — the 

 former division comprising Eleutherata, Ulonata (Synistata), and 

 Piezata, the latter Glossata, Antliata, and Rhynchota. It may 

 be objected with truth against this classification that many 

 so-called Mandibulata or Masticatores have but imperfectly deve- 

 loped mandibles, unfit for mastication, whilst many Haustellata 

 are without any vestige of an haustellum or sucking-tube. But 

 its principal defect seems to be that it disregards natural rela- 

 tionships in separating two orders so nearly allied as Piezata 

 and Glossata, and associating the latter with animals with whom 

 they do not agree as regards the structure of the mouth, except 

 inasmuch as the organs of the mouth are generally prolonged — 

 a circumstance which has no typical but merely a biological sig- 

 nificance. It is not, however, my intention by these remarks to 

 derogate from the importance of the organs of the mouth for 

 the establishment of principal as well as of subordinate divisions 

 of insects, so clearly demonstrated by the imperishable works of 

 the great Danish entomologist; nor do I deny that two principal 

 types are observable in the structure of the mouth in that class. 

 But I believe that their essential point of difi'erence has been 

 overlooked, and therefore an erroneous classification adopted. 

 This essential point of diflference is, in my opinion, to be found 

 in the position of the first two pairs of appendages of the mouth 

 with reference to the skull *. 



One of these two principal types is characterized by the man- 

 dibles ai-ticulating with the skull by means of a hinge-joint, while 

 the maxillae are connected with the skull througli a less perfect 

 ai'ticulation, sometimes merely sliding on its anterior margin, 

 which surrounds the mouth. This arrangement leaves the or- 

 gans of the mouth entirely free outside the mouth ; they can be 

 moved laterally, and are so far fit for biting; and whilst the 

 mandibles are altogether incapable of being protruded in front 

 of the mouth, the raaxillse are only in a very limited degree 

 capable of such a displacementt- The appendages of the mouth 

 cannot, therefore, be used as stinging-instruments ; and when 



* The first indication of this view may be found in a passage of the 

 important paper by Latreille, " De quelqnes Appendices particuhers du 

 Thorax de divers Insectes" (Me'm.duMuseum,1821,t.vii.p.20, conchiding 

 note, " La nature me parait avoir forme," etc.). But he has not carried it 

 out in practice ; otherwise he could not have placed Glossata amongst 

 Suctores. 



t The apparent protrusion of the proboscis in bees, which is formed by 

 the second and third pair of appendages of the mouth, consists principally 

 in its being stretched out, whilst ordinarily it is folded up ; but it is always 

 outside the mouth. 



