182 CALIFORNIA ACADEMY OF SCIENCES. [26] 



In at least certain groups of Coleoptera, sexual characters 

 should be considered generic when they are evinced by 

 such radically different modifications, for these imply 

 decided differences in the methods of exercising the func- 

 tions pertaining to reproduction, the most important act in 

 the lives of these organisms, and are the outward signs of 

 innate differences much greater than those made apparent 

 by mere external form. From a biological standpoint they 

 are the most important characters which can be assumed, 

 and in the present instance have an unquestionable value. 



I have, therefore, drawn up the following scheme of 

 genera, the differences being indicated by characters which 

 are non-sexual, and which readily serve for identification 

 irrespective of the more important differences which have 

 been indicated above. 



Head having two occipital foveas, not carinate laterally beneath. 



Pronotal foveas joined by an impressed line Rybaxis. 



Pronotal foveas three in number, generally not connected. 



Foveas subequal, large, all spongiose Bryaxis. 



Foveas equal, smaller, pucctiform Nisa. 



Foveas unequal and dissimilar. 



Lateral large, spongiose; median small, nude. . . Reichenbachia. 

 Head having no occipital foveas, finely and strongly carinate beneath later- 

 ally. 

 Pronotum having small, feebly-impressed, lateral fovtas and a very 



minute, more abrupt median puncture, all nude. Nisaxis. 



Pronotum devoid of foveas; elytral strias obsolete 1 ' 2 



Eybaxis Saulcy. — In our fauna this genus contains the 

 three species sanguined Leach, conjuncta Lee. and Brend- 

 elii Horn. 



Nisa n. gen. — There being no specimen of this genus be- 

 fore me at the present time, I cannot state positively 

 whether the head is laterally carinate or not, it is, how- 



'LeConte— Tr. Am. Ent. Soc. VIII, p. 183. 



-'The characters given for inornata Brend. indicate a very peculiar species 

 which warrants closer study than has yet been given it. As the occipital 

 foveas are wanting, it may be attached for the present to Nisaxis, but it prob- 

 ably possesses differential characters of generic value. 



