PSILOPUS. 



93! 



The first of my three species is described below as P. psittacinus; 

 the male js remarkable by a very uncommon structure of the wings ; 

 as Wiedemann's description of the male says nothing about such a 

 structure ; moreover, as neither the dust upon the face, nor the color 

 of the first abdominal segment, nor that of the feet agrees with the 

 male of P. psittacinus, it is therefore impossible to identify it with 

 Say's species. Of P. bicolor, described below, and distinguished by 

 its slender tarsi, I know only the female; it is very much smaller 

 than P. unifasciatus should be, according to Say's and "Wiedemann's 

 statements ; moreover, the wings are not light-yellowish, their veins, 

 however, dark-brown, the face covered with more dust, and the tarsi 

 much paler than they should be in the species of Say ; therefore 

 both cannot be taken for one and the same. The third of my spe- 

 cies, P. variegatus, of which, however, I possess also only the female, 

 has tarsi of a darker color than the two preceding species, though 

 the fore tarsi are not altogether and the hind tarsi not only at the 

 tip, black-brownish ; on the coutrary, the fore and middle tarsi are 

 blackish from the extreme tip of the first joint, the hind tarsi, how- 

 ever, entirely blackish with the only exception of the root of the 

 first joint ; moreover, the face is very thickly covered with dust, the 

 color of the wings not yellowish, and the color of the veins of the 

 wings not dark-brown, so that it would be entirely inadmissible to 

 declare this species for P. unifasciatus of Say, which therefore can- 

 not be found among the species known to me. Neither is there any 

 information about it to be derived from Wiedemann-Winthem's 

 collection ; there is no specimen in it which bears such a name, nor 

 is there any other to which the description of P. unifasciatus might 

 apply. 



4. patibulatus Say. Say's description agrees well with a species which 



is very common in North America, similar to sipho, but with black 

 feet and smaller ; it is described below more in detail under Say's 

 name. Wiedemann's description is but a translation of Say's de- 

 scription of this species, which he seems not to have possessed him- 

 self. 



5. femoratus Say. Judging from Say's description we refer this species 



into the circle of relationship of P. scobinator, calcaratus, &c. That 

 this is correct, is confirmed by a statement of Say, which otherwise 

 would have been rather striking. While he describes (Journ. Acad. 

 Philad. HI, 86, 5) the femora as green, and, with the exception of 

 the hind ones, provided with a pale tip, he speaks (1. c. VI, 168, 

 11) of one specimen with entirely pale femora. Now the males of 

 all the species, which belong to the above-mentioned group, have 

 the femora of precisely the same color as Say first described them, 

 while the females have entirely pale femora. The species, which 

 belong here, are distinguished in the male sex by some peculiarities 

 in the structure of the feet ; as Say's description does not mention 



