NORTH AMERICAN ACROLOPHIDAE — HASBROUCK 509 



morphology of the male genitalia of the primitive Lepidoptera, 

 basing his system largely upon the works mentioned above, but adding 

 much to the knowledge of the morphology and homology of these 

 structures. 



While the present revision introduces no new terms or concepts, 

 it is of some interest to note the author of each term and the date he 

 gave it the approximate morphological definition presently accepted, 

 as follows: Buchanan-White (1876), tegumen; Gosse (1883), uncus; 

 Smith (1890), harpes, clasper (of sacculus of harpe); Baker (1891), 

 saccus; Pierce (1909), vinculum, aedeagus, vesica, cornuti, sacculus 

 of harpe, cucuUus of harpe; Pierce (1914), anellus, juxta, manica, 

 costa of harpe, valvula of harpe, costal arm or process (of harpe), 

 transtilla, socii, gnathos; and, Busck and Heinrich (1921), penis. 

 Several of these structures are of importance because of their reduc- 

 tion or complete absence in the Acrolophidae. Although the works of 

 Buchanan-White (1876), Gosse (1883), Smith (1890), and Baker 

 (1891) are not cited in the present revision, reference has been made 

 to these workers by Eyer (1924). 



In the following characterization, the concepts of the above workers, 

 especially those of Busck and Heinrich, have been combined, con- 

 densed, and modified so as to apply specifically to the North American 

 Acrolophidae. Except for the penis and its associated structures, 

 the parts discussed below are generally considered as belonging to the 

 external genitalia. Only the ninth and tenth abdominal segments 

 are involved in the structure of the external genitalia. The eighth seg- 

 ment does not exhibit any genital modification and the presence of an 

 eleventh segment is not indicated. Although the exact defining 

 limits of the ninth and tenth segments are not determinable, it has 

 been indicated that the sclerotized structures surrounding the genital 

 opening (i.e., the vinculum, anellus, aedeagus, harpe, and transtilla) 

 are developments of sclerites of the ninth segment, while the sclerotized 

 structures surrounding the anal opening (i.e., the uncus and gnathos) 

 are developed from the tenth segment. 



The vinculum (vn, fig. 5), a modification of the ninth sternum, is a 

 ventral, sclerotized, U-shaped pouch articulating at its dorsal extrem- 

 ities with the tegumen and serving as a base of attachment for the 

 genital capsule. The saccus, a medio ventral anterior projection of 

 the vinculum, is absent. 



The anellus (an, fig. 2) is normally an undifferentiated, unscler- 

 otized, unarmed membrane situated within the ventral angle of the 

 vinculum and supporting the aedeagus which it surrounds in the form 

 of a cone. In a few species, it is partially sclerotized; in several others, 

 it is densely clothed with minute, seta-like processes. The juxta 



