CHARLES W. METZ. . 127 



P. pemisylva?iica, male, described by Cockerell from Penn- 

 sylvania specimens, agrees perfectly as far as the descrip- 

 tion goes, with the form of modestus having the lateral face 

 marks only slightly notched by the antennal sockets, and re- 

 ceding to a point on the orbital margin. Cockerell says of 

 this, "it looks most like modestus at a glance, but differs in 

 the shape of the face marks ". The shape of the face marks, 

 however, correspond to the form mentioned, so that no dis- 

 tinction of this nature can warrant specific separation. I 

 have examined a specimen of this in the Cockerell collec- 

 tion, and found nothing to distinguish it from modestus. 



P. citriuifrons, male, was described by Cockerell in 1896, 

 from Colorado specimens. This also agrees with the de- 

 scription of modestus as given, except in the " prothorax 

 dark, except yellow on tubercles ". I have the Baker collec- 

 tion containing the lot from which the type of this was taken, 

 and find in it several specimens without yellow on the collar, 

 but they are merely forms as indicated. Dr. Howard writes 

 that the species is known only by its unique type in the 

 National Museum, which would indicate that the specimen 

 is only one of those lacking the collar markings. 



P. triangularis, male, was also described in 1896 by Cock- 

 erell, from Georgia specimens. The description is very 

 complete in external characters, but gives nothing to distin- 

 guish the specimens from a form of modestus, having narrowed 

 upper lateral face marks. The description stated, "it might 

 be confounded with afHnis, but is larger, the supraclypeal 

 mark is much longer, and the wings are darker ". The size, 

 supraclypeal mark, and shade of wings are of no value, and 

 nothing else is given that could distinguish the specimen. 

 What Professor Cockerell probably took for affinis at that 

 time was a form of modesttis, for his description of the face 

 marks could not possible indicate P. zizice which has usually 

 been taken for affinis. 



P. sayi, male, was described in 1904, by Robertson, from 

 Illinois specimens. The only distinction given between this 

 form and that called illinoiensis, is that it has the lateral face 

 marks pointed on the eye margin and tegulae often with yel- 



TRANS. AM. ENT. SOC, XXXVII. 



