78 STUDIES IN NORTH AMERICAN MEMBR ACTU.E 



genus. Dr. Fitch himself wrote the name Cyrtosia and we 

 must so accept it. 



I have a fair recollection of the specimens from which Dr. 

 Goding drew up the description of his Smilia Vanduzii, later 

 placed by Prof. Baker in Cyrtolobus, and they certainly were 

 distinct from any species now before me. Cyrtolobus arcuatus 

 Emmons is nearest to ovatus described below but, judging from 

 his figure and description, it is more strongly sinuated post- 

 eriorly and the colors are darker with a transverse dusky band 

 near the hind angle of the crest. It is still unrecognized by me. 



In the following key I have attempted to arrange our sub- 

 genera and the species known to me so that the student may 

 be able to place any of them with reasonable certainty. 

 In the case of some of the closely related forms it has been 

 found necessary to make use of certain comparative characters, 

 an unsatisfactory expedient at best, but with a few of the well 

 known forms determined it should not be difficult to locate 

 the others. 



KEY TO THE SUBGENERA. 



Pronotum strongly inflated posteriorly, the crest forming an 

 inflated cyst before and behind the median pale spot, 



Xantholobus V. D. 



Pronotum not strongly inflated, the crest however, usually more 

 or less distinctly compressed on the median spot, 1. 



1. Dorsal crest low and sinuated at the middle; form elong- 



ated and much depressed, Evashmeadca Godg. 



-. Dorsal crest not distinctly sinuated above, 2. 



2. Crest highest anteriorly over or before the humeral angles, 



the dorsum sloping and nearly rectilinear to the apex, 



Atymna Stal. 



Crest regularly arcuated above in the more typical examples, 



or in any case with the highest point at or near the 



middle, Cyrtolobus Godg. 



Subgenus Cyrtolobus Goding. 



Dorsal crest strongly elevated and regularly arcuated from the 

 base of the metopidium, at most with a slight sinuation 

 posteriorly, 1. 



