106 
Psyche 
[June 
branches. Genital armature as shown in figure 3, B, C ; 
sedeagus longer than in prestoni. 
Female unknown. 
Holotype (<?) : No. 27664, Museum of Comparative 
Zoology; collected at Ualyaia, Paraguay; October (F. 
Schade). 
This species has much fainter wing markings than pres- 
toni, the wing as a whole appearing smoky. The 10th 
abdominal segment has more pronounced lobes than in 
prestoni, and the aedeagus is shorter. The hind wing is 
much more reduced than that of prestoni. 
N allachius americanus McL. 
Figure 4 
Pilar americana McLachlan, 1881, Ent. Mon. Mag., 18 : 
55 ; Banks, 1905, Trans. Amer. Ent. Soc., 32 : 24. 
N allachius americanus Navas, 1909, Mem. Beal. Acad. 
Cienc. Art. Barcelona, 7(17): 667; Carpenter, 1940, 
Proc. Amer. Acad. Arts. Sci., 74: 273; Steyskal, 1944, 
Psyche, 51: 183. 
The male genital armature and wings of both sexes were 
figured in my 1940 revision, but I include here drawings 
of the wings of the male in order to call attention to the 
anastomosis of the posterior branch of MP with CuA in 
the fore wing. The amount of anastomosis appears to 
be constant in the species. So far as I am aware, this 
venational peculiarity is unknown in the Old World Dila- 
rids, though it does exist in N. loxanus Navas, from Ecua- 
dor. If it were not for the striking similarity of the male 
genitalia of americanus and prestoni, I would consider 
this sufficient to separate the two generically. It is note- 
worthy, also, that there are fewer subcostal cross-veins 
in americanus than in prestoni. 
The surprising collection of twenty-seven specimens of 
americanus in Detroit, Michigan, has already been noted 
by Steyskal (1944). The species is now known to occur 
in Kentucky (type), Maryland, Virginia, and Michigan. 2 
In the Museum of Comparative Zoology there is also a 
2 But not California, as stated by Navas (Gen. Insectorum, 156: 1; 1914). 
