86 U.S. NATIONAL MUSEUM BULLETIN 24 4 



Antennae (fig. 377) broadly bipectinate, gradually decreasing in width 

 to apex, pectinations arising basally from each segment; sensory hairs 

 erect, very slender, approximately 4x diameter of pectination in length. 

 Legs (fig. 179) unarmed. Forelegs greatest in length, first tarsal 

 segment longest, greater than that of mesothoracic legs; second pair 

 of legs with femur slightly but distinctly longer than that of forelegs. 

 Posterior end of abdomen equalling extent of secondaries. 



Wings (fig. 162) evenly scaled, brownish fuscous. Forewing with 

 scales of cell very slender, hairlike, with acute tips; apical angle, 

 outer margin of both wings strongly rounded; primaries 11-veined; 

 R3 and 4 occasionally connate, usually stalked; base of M simple 

 within cell of both wings; lA completely absent; 2A smoothly curved 

 beyond departure of 3A spur, not angulate. Secondaries 7-veined; 

 Rs either fused with Sc+R for short distance or connected to it 

 by oblique crossvein as in B. tracyi; M2 and 3 usually separate, but 

 may be connate. 



Male genitalia. — In general, weakly sclerotized. Tegumen 

 without apical cleft. Valves with bases extended internally into 

 prominent apodemes; pul villi only slightly developed, minutely spined; 

 sacculus with apical spinules. Vinculum gradually tapering to 

 rather elongate saccus. Aedeagus simple. Eighth sternite with 

 shallow base; f ureal arms long, slender, divergent, either with or with- 

 out distal knobs. 



Female. — Unknown. 



Discussion. — Basicladus differs from the preceding genus Astala 

 in certain major features that are believed to be of generic value: 

 the loss of lA and the smoothly curved 2 A in the forewing; the 

 decidedly different structure of the male genitalia; the basal origin of 

 the antennal pectinations; and, most obvious, the broad, bluntly 

 rounded wings. Astala, in contrast, possesses an angulate 2A and 

 has some vestige of lA, pectinations that arise near the middle of 

 each segment, and wings with the apical angle more produced. 

 Eurukuttarus pileatus, closely resembling Astala in venation, agrees 

 with Basicladus in only one feature, the point of origin of the antennal 

 pectinations. Thus, Eurukuttarus also is very distinct from Basi- 

 cladus. 



The basal origin of the antennal pectinations, which is believed to 

 be of generic importance in the Psychidae, has suggested the name 

 "Basicladus" (basal branch). « 



Key to the Species of Basicladus 



la. Wing expanse 16-19 mm.; saccus as long as main body of genitalia (fig. 



273) 31. B. tracyi 



lb. Wing expanse 10-13 mm.; male genitalia with saccus less well developed 



(fig. 274) 32. B. celibatus 



