64 ILLINOIS BIOLOGICAL MONOGRAPHS [64 



A second group (Figs. 43-46) was distinguished by the loss of theta 

 on the prothorax and the association of kappa and eta on the abdomen 

 while epsilon remained below alpha and gamma on the prothorax and 

 the crochets remained in a complete circle. The Pyralidoidea and prob- 

 ably the Zygaenoidea have originated from these forms and have retained 

 all three distinctive characters except that the crochets have gradually 

 been reduced in number and groups of adjacent setae have been modified 

 into tufts. 



In the third primary division (Figs. 21-24 et al.), theta was lost on 

 the prothorax and epsilon migrated back to rho to cover the opening, 

 kappa and eta remained distant on the abdomen, and the crochets be- 

 came so limited in number as to reach less than half way round the pro- 

 leg, forming a mesoseries. From this division have arisen all the true 

 Macroheterocera, i. e., all the Macrolepidoptera except the Rhopalocera. 



Family Nepticulidae 



The immense number of species in the genus Nepticula causes one 

 to hesitate to make generalizations concerning the family. Many of the 

 larvae have been seen by entomologists, but very few species are familiar 

 to the writer. Descriptions in most cases neglect to state whether legs 

 are present on the thorax or crochets on the abdomen, whether the body 

 is moniliform, depressed or cylindrical, and what is the shape of the 

 front, altho they seldom fail to report whether the body is white or 

 greenish white and that the head is brown. 



In all the species of Nepticula examined, and in those described by 

 Wood (1894), both crochets and segmented thoracic legs are wanting; 

 there are two pairs of fleshy leglike swellings on the thoracic segments and 

 six pairs on the abdomen (Fig. 93) ; the head is flattened but compressed 

 rather than depressed ; the front is narrowed caudad ; the lobes of the 

 epicranium extend caudad to a considerable distance behind the meeting 

 point of the front and vertical triangle ; and there is a single large and 

 conspicuous ocellus on each side. 



Ectoedemia ohrutella, E. phleopJiaga, and Opostega nonstrigella 

 were also examined and show a similar structure except that the proleg- 

 like swellings seem to be absent. A careful study of the entire head 

 capsule and the tentorium will be necessary before these forms can be 

 intelligently classified. 



Family Prodoxidae 



The two well-known species of this family differ markedly, having 

 but three or four readily observed characters in common. The head is 

 not depressed as in many Aculeata, but is about as high as wide and is 



