40 



The imagines of the Thysbe form varied in the same brood in 

 the depth of the dentations on the inner margin of exterior band 

 on the fore wings. One specimen was almost without dentations, 



and one had them reaching- almost half way across the transpar- 

 ent space. There was also considerable variation in the shape of 

 the fore-wing. In some, always male, the wings were narrower 

 and more pointed than in others always female. This seems To 

 be a sex difference, though the difference is very little in some 

 cases. 



In the most, before flight, the transparent costal spot was cov- 

 ered with scales so as to be entirely indiscernible. These were 

 more or less lost upon flight, though more permanent than the 

 scales at first covering the central transparent portion of the 

 wings. 



The synonymy of the species stands so far as determined a^- 



follows : 



• Macroglossa Thysbe, Fabr. 



" Pelasgus, Cram. 



" cimbiciformis, Stephens. 



Dimorphic variety : 



Macroglossa ruficaudis, Kirby. 

 " uniforms, Grote and Robinson. 



" buffalotnsis, Grote and Robinson. 



" floridensis, Grote and Robinson. 



The form from Florida called floridensis differing in nothing 

 but size from ruficaudis is also found and more commonly, after 

 the Thysbe form. 



Whether Macroglossa fuscicaudis (Walk.) is a variety of this 

 species or not is as yet undetermined. It seems probable, how- 

 ever, that it is an aberration rather than a variety: hut is is 

 pretty surely the one or the other. 



Geo. D. Hllst. 



f—-\ Nyetobates permsylvanica. Beg. and 



P'niii N. barbata, Knock, resemble each other very 



VVi' ' Vi'/ mnch im< l as they are found both in the same 



— I — localities, we give here figures of the mentunu 



which present the best specific charaters by their shape and 



sculpture. 



a. Mentum of N. pennsylvanica, coarsely punctured. 



b. Mentum of N. barbata, clothed with hairs. 



CARL 1-IK'lls. 



