Classification of the Lepidoptera. 255 



On the other hand, the Micropterygidas have often been 

 compared with the Trichoptera, owing to their resemblance 

 in form and structure ; and the discovery of the jugum being 

 common to the two groups should go far to prove the deriva- 

 tion of the Lepidoptera from the Trichoptera, and to disprove 

 the alternative theory of a Hymenopterous ancestor based on 

 the resemblance between the larvae of Lepidoptera and of 

 sawflies. 



Dr. Chapman's discovery of the larva of the lower of the 

 two Micropterygid genera — Eriocephala — with its antennal and 

 anal appendages, complete set of legs to each somite, spicu- 

 late tubercles, and abdominal sucker, tends to complete our 

 knowledge of the group. 



After dividing the Lepidoptera into Jugataa and Frenatae, 

 Prof. Comstock proceeds to subdivide the latter into families 

 which retain the frenulum and others that lose it; but this is 

 certainly not a natural arrangement, as the loss of ttie frenulum 

 occurs in scattered genera in many families of Lepidoptera, 

 such as : — Himantopterus in the Zygasnidae ; the Arbelidae, 

 closely allied to the Cossidse ; Cleosiris in the Callidulidas ; 

 many genera of Drepanulidse, such as Phalacra, Drapetodes, 

 Oreta, and Gilix ; Ratarda in the Lymantriidas ; the Ura- 

 niidae, nearly related to the frenulated Epiplemidge ; and in 

 the Geometridaa, Hypulia and Genusa in the Boarmiinai, 

 and many genera of Geometrinaa. 



Prof. Comstock again subdivides his groups by the reduc- 

 tion of the inner area of the fore and hind wings, after 

 doing which he leaves his other families undefined till he 

 completes his study of them. But it is not correct to talk, 

 as he does, of the reduction of the inner area ; it is vein I c, 

 not vein 1 a, that becomes aborted in each wing, and it is only 

 in such families as the Saturniidaa, Endromiidae, Drepanulidaa, 

 and Geometrida?, where vein 1 a terminates on the inner 

 margin before the anal angle or is absent altogether, that the 

 inner area of the hind wing is somewhat reduced. The inner 

 area of the fore wing, on the other hand, is somewhat 

 extended by the migration of the subcostals, carrying with 

 them the cell from its original medial position, towards the 

 costa in order to strengthen that margin for purposes of flight — 

 the subcostal nervules becoming crowded close together and 

 their combinations more complex and liable to vary, and 

 characters based on them consequently of less value in the 

 higher than the lower forms. 



That the primary division of the Frenatas into " frenulum 

 losers " and " frenulum conservers " is faulty is recognized by 



18* 



