198 THE CANADIAN ENTOMOLOGIST. 



and Astoria, Ills., and I have now living material from an unknown 

 source, but taken at Washington, D. C. To this list of localities may be 

 added Lower California and Arizona, from the collection of Mr. Henry 

 Ulke, of this city. 



The close relationship of mercator to suriiiamensis makes reasonably 

 certain their virtual identity as regards development, nor is it probable 

 that they differ in any degree in food habits. 



The principal points of structural difference between these two 

 species may be best expressed in tabular form, thus : — 

 Tempora long, equal to about ^3 the diameter of the eye ; $ with side 

 margins of front strongly reflexed, and with trochanters large, termi- 

 nating in a spine surinamensis. 



Tempora very small, tuberculiform, equal to about 1-5 the diameter of 

 the eye ; (^ with side margins of front less prominent, trochanters 



unarmed -. mercator. 



A third species, S. bicornis, Er., also strongly resembling surinamen- 

 sis, and differing chiefly in having the side margins of the front developed 

 into two conspicuous horns, has similar habits, and as it is apparently 

 better known in Europe than mercator, may occur with us, though as yet 

 I have been unable to discover it. 



NOTE ON MAMESTRA. COMIS. 



BY A. RADCLIFFE GROTE, A. M. 



This species is described by me in Bull. Buff, Soc, N. S., III., 85, 

 not in the Geological Survey, as quoted in the Washington Catalogue. A 

 comparison of the description proves that the insect before me could not 

 have been M. olivacea. Its terms, both as to colour and markings, 

 completely cover the description of M. circumcincta. There can, of 

 course, be no reasonable doubt that the existing so-called "type" of 

 comis is a specimen of olivacea, in which case the type label has been 

 certainly transferred to another specimen after the type of comis was 

 returned to Mr. Hy. Edwards. I do not remember that my type of 

 comis was peculiarly set. The species was so much more vividly coloured 

 that it did not even suggest to me olivacea, a species of which I possessed 

 a long series. 



Mr. Carl F. Baker spends most of the summer collecting in 

 choice localities, up to 12,000 feet altitude, in the mountains of Northern 

 Colorado. After October ist, his address will be Auburn, Alabama, where 

 he goes to fill the position of Entomologist in the A. and M. College. 



