218 KANSAS UNIVERSITY QUARTERLY. 



hind tibia of the female has on the lateral surface near the flexor 

 border a row of four or five bristles, which occupy the middle 

 third or middle two-fourths of the tibia and are smaller than 

 those of the male ; on the same surface near the extensor border 

 there are four or five unequal and not equidistant bristles ; on 

 the mesal surface near the flexor border there are no bristles or 

 hairs, and on the same surface near the extensor border there is 

 one bristle, just as in the male. 



The wing is represented in figure 8. On both surfaces, at the 

 extreme base of the third vein, are from three to five small 

 spines. 



The squamulse are white, nearly hyaline, but the squamula 

 thoracalis has more or less of a brown tinge, and a part at least 

 of its dorsal surface is very finely but densely pubescent. 



Pyrellia sarcophagina v. d. Wulp. 



Jforellia sarcophagina v. d.Wulp, Biologia Centrali-Americana, Mexico. 



One male ; Corumba ; May. 



It is evident to one who studies Mr. van der Wulp's writings 

 on the Muscinte that for him the chief distinction between 

 Morellia and Pyrelb'a is the metallic color of the latter genus and 

 the non-metallic color of the former. Thus, he includes violacea 

 Fabr. and scapulata Bigot in Pyrellia, but assigns the present 

 species to Morellio. This is a grave error. Structural, not 

 coloration al, differences must be used for generic separation. 

 The characters which separate Pyrellia from Morellia are only 

 two : First, and much the most important, Pyrellia has a large 

 bristle on the flexor surface of the middle tibia which is never 

 present in Morellia; second, Pyrellia has (in all the species 

 known to me) the sterno-pleural bristles arranged 1:3, while in 

 Morellia these are 1:2 (in M. hipuncta Fabr. : 2). From the 

 structural standpoint this species must be assigned to Pyrellia. 



The bristles of the throax are represented in figure 9. Owing 

 to the position in which the legs have dried it is impossible to 

 get a perfect view of the bristles which protect the prostigma ; 

 there may be others than those indicated in the diagram. The 

 bristles of the legs are not particularly described by Mr, van der 

 Wulp. The femora are as usual in this genus, as is also the ante- 

 rior tibia. The middle tibia has on the anterior surface no bristles ; 

 on the flexor surface, one large one at junction of apical and 



