— 155— 



sternum longer and more developed, so that the front pair of legs are 

 more widely separated from the other two, which are approximated at 

 the back part of the sternum. This difference may most readily be per- 

 ceived by a comparison of Coenomyia and Hermetia or Stratiomyia. 



In the present and related families the second main vein-stem of the 

 wings gives off, first the sixth longitudinal vein, and, at a short distance 

 beyond, the fourth. In the family Syrphidae the reverse is invariably the 

 case in the two hundred or more species examined by me. The Conopi- 

 dae agree better with the Muscidae calypiratae in the origin of the fourth 

 and sixth veins occuring at the same point. 



Errata. —First paper, page 132, line 6, for "thickened" read flattened; 

 p. 134, under Xantbogramminae, B. for "Ocelli" etc. read Face retreating, etc.; 

 BB. for "Ocellar" etc., read Face projecting. Second paper, p. 11, line 6 from 

 bottom, insert usually after "wings". 



Yale College, May i88;. 



Notes on Platysamia Polyommata Tepper. 

 By Geo. D. Hulst. 



Platysamia polyommata Tepper, described from a unique Q in 

 Mr. Water's collection, Brookl. Bull. Vol. V, p. 66, and represented in 

 that place also by a photograph, is, as any one may see, an insect with 

 rather broader wings than P. cecropia L. and consequently without 

 doubt a Platysamia. Since then Mr. Waters has received from Arizona 

 a <$ of this same species. In coloration it is very like the 9- having 

 the same bands and spots on wings and body. It has in addition a 

 white basal crossband on the fore wings, and the black ground color is 

 richer and very velvety in appearance, The shape of the wings is how- 

 ever altogether different from those of the 9- In this it has almost the 

 form as it consequently has very much the appearance of Callosamia 

 promethea. The fore wings are just as distinctly falcate, and the external 

 margin runs inward, shortening the internal margin and narrow- 

 ing the wing. The hind legs are narrow and extent backward. 

 The insect is thus put in the unfortunate position, that the tf 

 is in one genus, the 9 i n another. Samia cynthia has gotten itself 

 in a somewhat similar predicament. In China it is a Samia but in the 

 few years it has been naturalized in this country, it has broadened its 

 wings, so it has become a pretty fair Platysamia. I call attention to 

 these facts only that those who are interested may see that some of these 

 genera have no excuse for existing as at present limited; for they are, I 

 believe, limited by the shape of the wings and the wing spots only: 

 neither of which characters are constant or identical in the sexes of the 

 same species. 



