1927 ] Study of the Male Abdominal Appendages of Apantesis 143 
sort of three sided investment. At its apical angle it is produced 
into two slightly diverging stout conical spines; proximally it 
tapers into a narrow ridge. In the figure a large portion of the 
callum is obscured, being overlapped by other parts. The sedoea- 
gus of phalerata is unique not only in external structure, but the 
vesica also differs in form from that of the other moths of the 
group. The sedoeagus was found to be variable in regard to the 
terminal spines, about one out of every four specimens examined 
showing some departure from the normal evenly bifid structure; 
such variation ranged from* a slight irregularity in size of the 
spines to complete absence of a spine on one hand, and on the 
other the addition of a third spine ; the presence of a third spine 
appears to be due to the bifurcation of one of the existing spines, 
rather than the production of a new one. Several such aberra- 
tions are shown in Figs. 35-38. 
The moths used in this study were sorted into four groups 
before beginning the study of the genitalia and the structural 
differences were found to correspond with the separation on 
superficial characters, with two exceptions. One specimen was 
included under phalerata which structurally proved to be radians, 
and a specimen of vittata was also found under phalerata. Each 
of these specimens was atypical in maculation and represented & 
borderline variation; the genital structures, however, were per- 
fectly typical. It is worth noting that while phalerata is the most 
protean of the forms and most apt to cause confusion by the 
similarity of its variations to the other forms, it differs the most 
in structure. In making determinations it is necessary only to 
remove a few hairs to expose the long narrow terminal projection 
of the clasper characteristic of phalerata. With phalerata elimi- 
nated, of the remaining three forms nais is recognized by its 
black costa, while vittata and radians usually differ in the color- 
ation of the hind wings. 
Nais and vittata are found to be very similar structurally but 
a constant tho slight difference occurs in the sedoeagus. Radians 
differs from them in the multiple spines of the sedoeagus, and for 
the most part the claspers are characteristic tho they may re- 
semble vittata. Study of a larger series of radians would be de- 
sirable. Phalerata shows a surprising degree of divergence from 
