ANTENNA OF LEPIDOPTERA. 29 



The MrCROPTERYGiD.T5. — The members of this family have the 

 most generalized antenuaj of any of the living Lepidoptera. As 

 has been already noted, I find two types of antenna in the same 

 genus. Micropteryx semipurpurella has already been described 

 somewhat at length in the chapter on the evolution of the antennae, 

 and may stand as a representative of the simpler type. It is so 

 generalized in structure that I can find in it no character which 

 would distinguish it from some of the Trichoptex'a. Compare it with 

 Mystacides nigra, and the striking re?*emblance in structural cliarac- 

 ters will be evident. Nor is the resemblance superficial only. The 

 clothing of scales is practically alike in form and arrangement, the 

 same organs exist in both. The only appreciable difference is in the 

 number and relative length of the segments, neither of which char- 

 acters can be regarded as of any great taxonojuic value among the 

 Lepidoptera. The second type exhibits a remarkable peculiarity in 

 the arrangement of the scales. ]Most of them are gathered into two 

 radiating tufts and have their origin in two circular or oval depres- 

 sions, one on each side of the distal half of the segment. This is a 

 unique specialization, and I have no idea of its purpose. Fig. 51 

 represents a segment of the antenna of a male Micropteryx seppela (?) 

 and shows this arrangement of scales. M. purpurella has the same 

 arrangement on a much smaller scale, and other species vary between 

 these extremes. Another indication of the higher specialization of 

 this type is the presence of very broad, short scales on the scape and 

 pedicel in addition to the ordinary covering of long narrow ones. 

 There are also numerous long curved sense-hairs of the second type 

 which form a sort of pointed sheath around the segment and give it 

 the appearance of that of Anabolia bimaculata, one of the Tri- 

 choptera. 



A comparison of the antenna^ of the He})iali(Ue and Micropter- 

 ygidae will show that those of the former family are more highly 

 specialized. Aside from tlie specialization in the scales just noted, 

 the antennte of the Micropterygidte are very primitive. Pits and 

 rods do occur, but in no case have I been able to find more than a 

 single one to a segment, while in the Hepialidoe there are often many. 

 The nearly naked surface of the clavola in Hepialm must also be 

 regarded as an indication of a higher type. 



FRENATiE. 



The suborder Frenatte is divided by Professor Comstock into two 

 principal sections: the Generalized Frenatie, including those fami- 



TRANS. AM. ENT. SOC. XXIII. I'EBRUAEY, 1896. 



