40 SYNOPTIC KEY 



24(28) Prolegs absent from one or two segments immediately 

 in front of the last segment. 25 



25(26, 27) Five pairs of prolegs present. (Comstock, 191 ; in part, 

 Lutz, 115 and 485.) Order Lepidoptera 



26(25, 27) Two, three, or four pairs of prolegs present; absent from 

 more than two of the anterior abdominal segments; 

 animal advances by a looping movement. Almost 

 entirely Geometridae. (Lutz, 192; Comstock, 287.) 



Order Lepidoptera 



27(25, 26) Four pairs of prolegs present; absent from the last 

 segment. Chiefly Tineoidea. (Comstock, 246; Lutz, 

 198.) Order Lepidoptera 



28(24) Prolegs present on the last segment only, or when pres- 

 ent on more than one segment, the additional ones on 

 consecutive segments immediately in front of the last, 

 never with five pairs. (Lutz, 280; Comstock, 494.) 



Order Coleoptera, in part 



29(1) Without jointed thoracic legs. 30 



30(32) Aquatic forms (i.e., capable of living beneath the 

 water). 31 



31 With abdominal prolegs, or entirely legless; in the 

 more degenerate forms, the head is reduced and 

 retracted within the pointed apex of the thorax; no 

 appendages of the imago are visible, and the pupa is 

 formed within the contracted and hardened larval 

 skin. (W. and W., 943.) Order Diptera, in part 



32(30) Non-aquatic (i.e., not capable of living under water). 



33 



33(40) With conspicuous head and mandibles, unjoin ted 

 rudiments of the thoracic legs frequently present, 

 body usually not tapering at the anterior end. 34 



