LARVAL FORMS OF COLEOPTERA 



certain Polyphaga larvae (though not necessarily of primitive fami- 

 lies) likewise show an indication of a separate tarsus and claw (see 

 footnote 5, p. 9). In neuropterous larvae, as Baphidia, Siolis, and 

 Corydalis, a distinct tarsus and two claws are present and in many 

 other respects the greatest similarity exists between them and the 

 typical Caraboidea. Unquestionably, however, these neuropterous 

 larvae are less primitive than the primitive polyphagous Staphyli- 

 noidea (p. 25). It would therefore be logical to place the Ade- 

 phaga as the third suborder, as it is the more modern of the three, 

 and the Polyphaga before it, because the suborder Polyphaga in- 

 cludes existing larvae of a primitive type from which its other larval 

 types can be derived directly or indirectly. But for practical pur- 

 poses it appears more advisable to rank the suborders in the com- 

 monly accepted sequence, and as no traceable phylogenetic connec- 

 tion exists between them, the sequence in which they are placed and 

 treated is rather immaterial. 



The primitive type of the Polyphaga is found in its most charac- 

 teristic and original form in the series Staphylinoidea as limited in 

 the present paper, more particularly in such families and subfam- 

 ilies as the Limnebiidae, Leptinidae, and Anisotomidae ; and it is 

 from the larval type found in these families that are derived not 

 only the more or less specialized larvae of the other staphylinoid 

 families but also the different types of the hydrophiloid larvae (p. 

 31), possibly through larvae of such families as Hydroehidae and 

 Spercheidae. 



The larva of the series Byrrhoidea (p. 43) represents a second 

 distinct polyphagous type which, while primitive, is in some re- 

 spects less primitive than the larva of the primitive Staphylinoidea. 

 Probably the two series have ancestors in common, but by no larval 

 type known up to this time are they linked together. However, 

 some of the derived families of the byrrhoid type and some be- 

 longing to a third distinct polyphagous type, the cucujoid type, 

 approach one another, and about the direct afifinities between the 

 Cucujoidea and the Staphylinoidea there can be no doubt. Rather 

 isolated as the series Byrrhoidea appears in the polyphagous 

 suborder, it does not seem necessary to rank it and the families 

 and series derived from it as a separate suborder. Two series, the 

 Dascilloidea (p. 43) and the Cleroidea (p. 55), are descended 

 directly from the Byrrhoidea, supposedly through heterocerid 

 forms and dermestid forms, respectively. 



From the byrrhoid family the Byrrhidae (p. 43), the Dryo- 

 poidea (p. 44) can be derived through the dryopoid family Ptilo- 



7 



