146 U.S. NATIONAL MUSEUM BULLETIN 24 4 



Some evidence exists that the cases of this species (or at least of 

 larva bags quite similar to 0. westwoodii) are sexually dimorphic. 

 In a group of cases collected by Paul Koehler on Proso'pis species from 

 La Rioja, Argentina, this dimorphism was very obvious. From a 

 series of 49 bags, 27 leaf-covered bags had been made by larvae that 

 produced male moths, and 20 leafless cases contained females. I 

 found only two exceptions, bags that had produced females but were 

 heavily covered with leaves. No intermediate conditions were pres- 

 ent in this series. 



I examined one adult male that had been identified questionably by 

 Koehler as 0. westivoodii. This specimen is indistinguishable from 

 the males of 0. geyeri, and it actually may represent that species. In 

 addition, this specimen possibly may have been the moth upon 

 which Koehler's description (1939) was based. 



Material examined. — 1 cf , 65 cases: 



Argentina: Specific locality unknown, cf (identification questionable), ZSBS. 

 Catamarca, 3 cases, DEI; 6 cases, ZSBS. Coronel Vidal, 7 cases, DEI. La 

 Rioja, 49 cases, USNM. 



Adult Males Unkno^vn 



Many names in this family unfortunately have been proposed 

 on the basis only of the larval case and sometimes on the female pupae. 

 The males of these supposed species still are unlmown, or they can 

 not be associated with the described pupae and/or cases with any 

 certainty. 



Female pupae apparently have some characters that may be of 

 taxonomic importance (Koehler, 1939); however, this needs to be 

 studied further in a greater variety of species. The importance may 

 be limited primarily to specific identification and may not be ap- 

 plicable as a generic criterion. The taxonomic significance of the 

 larval case is even less than that of the pupa; considered alone, it is 

 generally a poor and sometimes misleading specific criterion. There 

 are instances, however, in which the case may be of prune importance, 

 but these examples are in a defmite minority. 



In New World psychids, the characteristics of the adult male 

 furnish the basis for both specific and generic separation. Also, 

 certain species known only from the miniature stages, even if recog- 

 nized as specifically valid, cannot be referred safely to the correct 

 genus. Thus, I have thought it preferable to include species based 

 on female specimens or immature stages in this separate section. 



In a description of a larval case httle possibility exists for diagnostic 

 features to be overlooked or for errors to originate because of mis- 

 interpretation of structure. For this reason and the fact that the 



