20 Introduction 



For similar reasons primitive elytra would be elongate, pubescent, 

 and imperfectly adapted to the other parts of the body, because in the 

 highly specialized beetles of each sub-order, they are short, glabrous, 

 and veiy perfectly adapted to the parts they adjoin. 



The hind wings in the primitive beetle should be efficient in flight, 

 with veins similar to those of a generalized insect, i. e., joined by cross- 

 veins, if the studies of Comstock and Needham are accepted. 



The abdominal segments would be the largest number known in 

 existing forms, viz: eight. 



The antennse would be composed of eleven, similar, unmodified 

 joints, pubescent, not geniculate. 



The palpi would be composed of four, similar, unmodified joints; 

 the triangular and securiform modification of the last joint are a special- 

 ization in one direction, often seen in Polyphaga; the gradual loss of 

 flexibility and prominence, which attains its maximum in Rhynchophora, 

 is apparently a specialization in an opposite du-ection, or atrophy from 

 disuse. 



The occurrence of ocelli is rare in beetles and is a primitive char- 

 acter, because ocelli are present in lower orders and lacking in the higher 

 Coleoptera. In Cicindelidse they are present in the larva only. 



The presence of certain sutiu-es, viz: the double gular suture, the 

 propleural sutm-e and the suture between the 2d and 3d abdominal 

 pleurae is a primitive character, because the general progressive modifi- 

 cation from an elongate, loosely organized creature to a short, compact 

 insect, with all its parts closely co-adapted, could only be accomplished 

 bjf a fusion of parts that would obliterate such sutures. 



The occurrence of some appendages to the legs, viz: membranous 

 appendages to the claws, membranous lobes beneath the tarsi, the 

 onychiuni (or arolium) and paronychium between the claws (treated 

 by some authors as representing the pulvillus of lower orders) and the 

 more or less distinct trochantin, is also an indication of prunitive char- 

 acter; such appendages are never found in highly speciaUzed beetles. 

 The trochanter also in the exaggerated form found in some Carabidse 

 and Lampyridse is a primitive character, being greatly reduced in special- 

 ized beetles. 



In certain families, like Staphylinidse, the effect of this modification 

 of the general form is also seen in the character of the coxse and their 

 cavities, the broad and prominent coxse being the primitive forms, 

 often accompanied by an unusual development of the trochanter. The 

 open coxal cavity, appertaining to a loosely organized beetle, is more 

 primitive than the closed cavity. 



