NO. 6 RICHARDS : NOCTUOID MOTHS 237 



shown that the usual "pollex" of agrotids is probably the true clasper 

 which has migrated to the ventral margin of the valve. P. conwayi has its 

 true clasper in the normal position though much reduced (approximate- 

 ly as in Peridroma (Hemieuxoa) microstigma, see Forbes, /. c). Also 

 the "pollex" of P. conwayi is quite different in appearance and association 

 from the "pollex" of Graphiphora, etc., and, accordingly, seemingly not 

 homologous with the similarly placed structure of those genera. The "pol- 

 lex" of P. conwayi is connected by a definite line of sclerotinization to the 

 normal position of the digitus just distad to the clasper-ampulla near the 

 costal margin of the valve. It seems logical therefore to consider this 

 structure as the digitus. The terminal macrosetae are unique. 



P. conwayi is a distinctive species not close to any described new world 

 agrotid. Making comparisons with other species is difficult in the absence 

 of close relatives. Obviously conwayi belongs to the neotropical Peri- 

 droma complex; it differs from the genotype {margaritosa Haw.) by the 

 peculiar uncus, lack of spines in the aedoeagus, the digitus migrated to the 

 ventral margin of the valve and bearing terminal macrosetae, and the 

 generically insignificant antennal pectinations. If the "pollex" of conwayi 

 were not considered the digitus, then this species would differ also in 

 lacking a digitus and possessing a pollex, but this interpretation is not ac- 

 cepted by the author. Two of the above differences from typical Peri- 

 droma, namely, the uncus and aedoeagus, are as in the related neotropical 

 genus Anicla (type infecta Ochs.) which is, however, different in many 

 other structural characters.^ 



On the whole, conwayi seems closer to typical Peridroma than to the 

 subgenus Hemieuxoa (type rudens Harv.), a detailed study of which is 

 given by Forbes, /. c. Considering the extensive variation of this type of 

 genitalia in the genus Peridroma sensu latu, it seems best not to erect a 

 new genus or subgenus for this peculiar species but to place it in the typi- 

 cal subgenus of Peridroma and to point out its additional similarities to 

 the closely related genus Anicla. 



AMPHIPYRINAE 



Platysenta ruthae (Schaus), new combination 



Perigea ruthae Schaus, Zoologica, 5 :35, pi. 1, fig. 5, 1923. 

 Cartago Bay, Albemarle Island; January 21, 1938; 



J. S. Garth. 1 cf 



6 National Museum of Canada, Bull. 55, p. 42, fig. 20, 1928. 



