Introduction 5 



though Dr. Gahan describes the suggestion that they are not really 

 a natural series as " heresy," ^ for, if the definition were strictly apphed, 

 the series would include Hyclroporus among water beetles, many Silphids 

 and Staphylinids, and many Clavicorns, as well as the Tenebrionid-like 

 beetles, for which it was intended. Even in that restricted sense, the 

 heteromerous tarsi do not afford a good definition, as may be noted in 

 comparing Tetratomini and Triphyllini, formerly far apart, now united 

 by Casey,'- or Ababa and Othnius, considered allies by that author, though 

 Ababa was later shown to be a Clerid by Schaeffer.^ Heteromerous 

 tarsi are in fact found in so many groups that the character cannot 

 safely be used to define a primary division or to found a natural series. 

 Nevertheless the reader will note as the more recent systems are explained 

 how their authors have clung to the tarsal system and especially to the 

 heteromerous division. 



Leconte System 



The great merit of the Leconte system is the primaiy use of many 

 other characters ch-awn from the sutures, palpi, abdominal segments 

 and antennae, guided tlu-oughout by Dr. Leconte's wonderful instinct, 

 which led him so nearly right that few changes in his system, out of the 

 many that have been proposed, meet with general approval. He was, 

 however, bound to be influenced by his early studies and the ideas 

 thereby derived from his illustrious predecessors, such influence, as it 

 seems to me, showing in his divisions Isomera and Heteromera, based 

 upon the formerly used tarsal characters. He divided beetles into: 



I. CoLEOPTERA Genuina: — double gular suture and flexible palpi. 



1. Isomera: — all the tarsi of same number of joints, 

 a. Adephaga — first visible abdominal segment divided. 

 6. Clavicornia — clavate antennae. 



c. Serricornia — serrate antennae. 



d. Lamellicornia — lamellate antennae. 



e. Phytophaga — 4-jointed tarsi 



2. Heteromera — heteromerous tarsi. 



II. Rhynchophora — single gular suture and rigid palpi. 



This is the system in general use in America. The objections that 

 have been urged against it are that the tarsal character can only be used 

 with exceptions, that Clavicornia and Serricornia merge one into the 



'The Entomologist, December, 1911, p. 395. 

 = Journ. N. Y. Ent. .Soc. VIII, 1900, p. 167. 

 ' Jouru. X. V. Ent. Soc. XXV, 1917, p. 13.3. 



