23 



have personally examined, is a 5 and not a 9 as stated by Strecker; 

 figure 5 is a specimen agreeing very closely with it. There is also 

 a S , one of the original type lot, in Dr. Barnes' collection. Dr. Dyar, 

 misled by the type labels on the Neumoegen specimens, described the 

 S of neumoegeni under the name aryxna. As, however, our studies 

 of the group have shown us that there are two forms, both included 

 in the type series of aryxna, which, while very closely related, show 

 certain constant differences in genitalia, at our suggestion Dr. Dyar 

 has restricted the name aryxna to the unnamed form of which fig. i 

 represents a co-type. We have examined over 150 $ specimens of 

 these two forms and about 10 9 9 ; in every instance the 9 could be 

 separated at once on wing pattern, the yellow band on primaries being 

 much broader and either touching or broadly coalescing with the 

 costal spot at end of cell ; in the $ these two yellow areas are always 

 broadly separated by the black ground color ; in the specimen shown 

 in fig. 5 they are most approached of any we have seen. In examin- 

 ing a long series of $ specimens we were struck by the fact that 

 some individuals appeared considerably stouter and chunkier in gen- 

 eral appearance ; these on being separated showed certain points of 

 maculation, notably in the shape of the second yellow spot from anal 

 angle on primaries, which strengthened us in the belief that we had 

 two forms before us ; finally a study of numerous slides of genitalia 

 provided us with still further proof, distinct constant differences in 

 proharpe and penis made a separation inevitable ; the slighter form re- 

 tains the name nciimocgciii, agreeing as it does with the S type in the 

 Strecker collection, the stouter form, about which we will speak in 

 more detail later, is aryxna Dyar. 



The S neumoegeni shows considerable variation in the size and 

 shape of the subterminal row of yellow spots on both wings. The 

 general tendency seems to be for the spots to decrease in size, as 

 shown in figure 6; such specimens are easily separated from M. 

 aryxna Dyar. In certain specimens, however, an inverse tendency is 

 shown, the spots forming an almost continuous band ; such specimens 

 when above the normal size, are easily confused with aryxna, and it 

 is very hard to definitely state any one feature by which a separation 

 is possible. As a rule neumoegeni is a smaller and slighter species ; be- 

 sides this the following points of distinction might be mentioned, but 

 as each is subject to considerable variation it is rather a combination 

 of characteristics than one definite feature by which the separation of 



