BAGWORM MOTHS OF THE WESTERN HEMISPHERE 45 



Discussion. — The basis for the generic separation of Prochalia and 

 the following genus, Zamopsyche, is not supported by ample evidence; 

 indeed, Zamopsyche could ahnost be considered a subgenus of Pro- 

 chalia. The major features of generic importance are the differences 

 in the wing structure of these two groups. The presence or absence 

 of tibial spurs alone cannot be considered of generic value, but often 

 the factor does suggest a large degree of difference in this family. 

 Likewise, the divergence in wing shape between these two genera 

 suggests an important separation. I have placed the greatest em- 

 phasis in delimiting the two genera upon the wing venation, even 

 though this appears to be quite variable in both groups. The basic 

 pattern, however, which can be ascertained by examining a series of 

 specimens, is fundamentally different, and it is believed to be of 

 generic value. 



The instability of the genetic factors controlling the pattern of 

 venation in these two groups, as well as the great similarity between 

 them in the female genitalia, male genitalia, larval cases, and other 

 characters, all suggest a more or less borderhne example of generic 

 differentiation. Prochalia and Zamopsyche are retained as sepa- 

 rate genera for the sake of uniformity in treatment and because such 

 a basic venational difference (namely, 12 veins in the forewing of 

 Prochalia versus 11 in Zamopsyche) is almost never encountered 

 within any of the New World genera recognized in this paper. 



5. Prochalia pygtnaea Barnes and McDunnough 



Figures 5, 67, 153, 172, 192, 247, 247a, 299, 322, 365; Map 1 



Prochalia pygmaea Barnes and McDunnough, Contr. Nat. Hist. Lep. N. Amer., 

 vol. 2, no. 4, p. 171, 1913; Check List Lep. Boreal Amer., no. 4808, 1917. — 

 Grossbeck, Bull. Amer. Mus. Nat. Hist., vol. 37, p. 105, 1917. — Dyar, Insec. 

 Inscit. Menst., vol. 11, p. 4, 1923. — Jones and Parks, Tex. Agric. Exp. Sta. 

 Bull. 382, p. 31, figs. 15, 21, 1928.— Gaede in Seitz, Macrolep. World, vol. 

 6, p. 1179, pi. 169b, 1936.— McDunnough, Check List Lep. Canada and 

 USA, pt. 2, no. 9534, 1939. 



Male. — (Fig. 5) Body and wings brownish fuscous. Antennae 

 (fig. 365) 18-19 segments. Wings (fig. 153) broader, usually shorter 

 than in Zamopsyche commentella, uniformly scaled, discal scales 

 (fig. 322) of forewings relatively broad, oblanceolate with acute 

 apices. Wing expanse 12-15 mm. 



Male genitalia. — (Fig. 247.) As described for genus. 



Female. — As described for genus; length 6-7 mm. 



Female genitalia. — (Fig. 299.) 



Case.— (Fig. 67.) Length 13-16 mm.; diameter 2-3 mm. Broad 

 anteriorly, tapering posteriorly; appearing relatively smooth to 



