82 BUKLETIN 132, UNITED STATES NATIONAL. MUSEUM 



weakly haired at base; spine cluster Spc^ rarely absent (in type and 

 furfurana) , when present developed as a strong ridge of spines upon 

 a free arm projecting over cucullus; spine cluster Spc^ present. 

 Tegumen short, broad, roundly arched. Uncus short, stout, with a 

 row of strong spines on inner side at margin. Socii small, flexible, 

 weakly haired. Gnathos simple, weakly chitinized. Aedoeagus 

 moderately long to A^ery long, stout, more or less curved; cornuti a 

 <'luster of two or more short spines, rarely absent. 



Female genitalia with signum a small flat scobinate patch. Duc- 

 tus bursae moderately long, simple. 



A compact easily distinguished genus of rather wide distribution, 

 showing, in genitalia at least, rather marked affinities to Endothenia. 

 The male genitalia are quite characteristic. There appear to be two 

 types of harpe: the lanceolana type with spine group Spc^ absent 

 and the cucullus spines dense and slender; and the verutana type 

 with 8yG^ strongly developed and upon a free arm, and with the 

 cucullus spines fewer but extremely stout (compare figs. 44, 46). 

 Otherwise the genitalia are of the same general type, with slight but 

 clear-cut specific differences. 



In pattern and markings the species are variable, and grade into 

 each other. This has caused considerable misidentification and con- 

 fusion. Except for the more strongly and characteristicly marked 

 specimens, accurate and certain determination is only possible by 

 means of the genitalia. The f olloAving specific key is drawn for such 

 typically marked examples, and will help to identify them, but will 

 not serve for all specimens of any given species. 



KEY TO THE SPECIES OF BACTEA 



1. Fore wing with outwardly angulate dark basal patch; if incomplete, at least 



indicated by outer dark margin on costal half (2) furfurana. 



Fore wing without such basal patch ; dark basal markings not reaching 

 to costa .. 2. 



2. Fore wing with a strong, straight, continuous, central longitudinal fuscous 



shade from base to apex 3. 



Fore wing without such ; where there is a continuous dark streak from 



base to apex the latter is sharply angulate at end of cell 4. 



'A. Dark costal geminations on fore wing very short (6) maiorina. 



Dark costal geminations long (7) priapeia (part). 



(8) sinistra. 

 4. Fore wing with a conspicuous white dot at end of cell. 



(4) verutana albipuncta. 



Fore wing without such 5. 



ii. Dark markings on disk forming a more or less interrupted longitudinal 

 streak, or a longitudinal streak at base and a short transvere streak across 



end of cell, hooked at its lower extremity (1) lanceolana. 



Dark markings on disk two round or elongate blackish spots, one near base, 

 the other at end of cell 6. 



