6 tr.S. NATIONAL MUSEUM BULLETIN 255 



southward through San Diego County and probably into Baja Cali- 

 fornia. These authors further state that the two forms meet at an 

 apparent zone of intergradation in the southern San Jacinto Mountains, 



Morphology 



A thorough morphological study of this subfamily has not been 

 attempted, although certain anatomical areas (e.g., mouthparts, 

 genitalia), due to their obvious importance, have been treated in 

 some detail. Most structures are discussed adequately under the 

 particular genus or species concerned, or in other easily available 

 references and will not be reviewed here. A few structures, however, 

 deserve special emphasis and are discussed in the following 

 paragraphs. 



Mouthparts. — Certain modifications of the maxillary appendages 

 have developed in a few species which deserve special consideration. 

 In general, the maxilla is of a primitive type, possessing palpal seg- 

 mentation similar to the Micropterygidae. The lacinia, however, has 

 been lost, and the galeae extended, but they are still rudimentary in 

 some respects. Each galea is circular in cross section and does not 

 unite with the opposing member to form a common feeding tube, or 

 tongue. A faint, longitudinal line (fig. 40) is present on the median 

 surface of each galea, and it probably represents the rudimentary 

 groove, which, in the higher Lepidoptera, becomes the food canal. 



The females of two genera, Tegeticula and Parategeticula, possess a 

 pair of extremely specialized structures, commonly referred to as 

 maxillary "tentacles," which arise from the base of each maxillary 

 palpus. Until the discovery of Parategeticula pollenifera, these struc- 

 tures were beheved to exist in no other genus of Lepidoptera except 

 Tegeticula. Other genera of Prodoxinae, now unknown, may be 

 found to possess this specialization; however, it is very unhkely that 

 any species not a member of this subfamily will be so equipped, because 

 the maxillary tentacle probably has evolved only once throughout the 

 order. 



The homology of the tentacle was studied by Smith (1893), who 

 concluded that it was an extension of the palpifer and was homologous 

 to comparable structures in certain Neuroptera, Mecoptera, and 

 Diptera. Smith's conclusion may be correct, but presently this is 

 difficult to ascertain and will remain so until more comparative work, 

 involving studies of musculature and embryology, can be conducted. 

 It should be emphasized, however, that if the first segment of the 

 maxillary palpus in Tegeticula is in actuaUty the palpifer, then tech- 

 nically the number of palpal segments in the Incurvariidae and related 

 families is one less than is apparent. This would be true because, as 

 defined (Snodgrass, 1935), the palpifer is a lobe of the stripes and not 



