8 U.S. NATIONAL MUSEUM BULLETIN 255 



These organs were first noted in the higher Lepidoptera by Rath 

 (1887, 1888) and in the more primitive gToups by Busck and Boving 

 (1914) and Tillyard (1923). In the Micropterygidae (fig. 53) and 

 Eriocraniidae, the sensory area is represented merely by a depression 

 lined with what appear to be rows of sensory cones. A comparable 

 organ, which I consider homologous, is present in the Prodoxinae as a 

 sac-hke invagination from the apex of the palpus. In this subfamily, 

 it is best developed in the genus Agavenema (fig. 44), being more 

 reduced in Tegeticula, Prodoxus, and Mesepiola. In Parategeticula 

 the organ is even less developed and is situated at the apex of the 

 second palpal segment. 



Wings. — In addition to venational characters and the distribution 

 of aculeae over the wing surface, another interesting, although often 

 neglected feature in the wings of Lepidoptera is the development of 

 the wing coupling mechanism. The subject has been studied carefully 

 by Braun (1919, 1924) and should be noted here, especially since some 

 interspecific variation apparently exists. 



The males of all genera, except Parategeticula, characteristically 

 possess a stout, single-spined frenulum (e.g., fig. 45). In Parategeticula 

 the frenulum is absent, and the humeral area of the hindwdng subse- 

 quently has become expanded to compensate for the loss. This rather 

 unique coupling mechanism is assisted in its function by the presence 

 of a row of stout spines arising from the base of the costa. 



The frenulum in all females is rudimentary and is represented only 

 by a few short, weak spines at the distal end of the costal sclerite. 

 Beyond this arises a row of spines which vary in structm-e according 

 to genus and sometimes species. In Prodoxus, Mesepiola, and Aga- 

 venema, the spines are approximately the same size, gradually becom- 

 ing more scalelike outward. The females of Tegeticula yuccasella and 

 T. synthetica have two or three basal spines of this series greatly 

 lengthened; thus, resembhng the true female frenulum of most higher 

 moths. The costal spines of T. maculata are generally more similar 

 to those of Prodoxus. The coupling apparatus in Parategeticula is 

 essentially the same as that described for the males; i.e., with an 

 expanded humeral angle of the hind wing comparable to the condition 

 that exists in the Lasiocampidae. 



Male genitalia. — The terminology used in this paper for the com- 

 ponents of the male genitalia (figs. 92-94) is essentially the same as 

 that followed by Klots (1956). The application of a few terms is 

 rather uncertain, however, and requires fm^ther discussion. 



Much of this uncertainty is illustrated by two somewhat different 

 interpretations (Eyer, 1924, 1926; Bastida, 1962) which have 

 appeared on the morphology of the prodoxid genitalia. In her paper. 



