314 CALIFORNIA ACADEMY OF SCIENCES. 



being unidentate within, while in Bryonomus they are dis- 

 tinctly bidentate. The maxillae and maxillary palpi of these 

 genera are figured on the plate, and it will be seen that they 

 also present important differences in form. 



Bryonomus differs from Cafius, or more properly Remus, 

 as the Californian species approximate much more closely 

 to this genus than to the European Cafius, in the compara- 

 tive shortness of the terminal joint of the maxillary palpi, 

 and verv greatly in appearance. The intermediate coxa? are 

 also widely separated, while in the others they are nearly 

 or quite contiguous, and, although generally in this group 

 the latter cannot be depended upon as a generic character, 

 it appears to be of much more importance in that portion 

 immediately allied to Cafius and Eemus. 



In the two species canescens and seminitens, the former has 

 the mesosternal process rounded behind and the mandibular 

 teeth rather small and equal, the latter has the mesosternal 

 process squarely truncate behind and the mandibular teeth 

 very unequal in size, the smaller being minute and on the 

 inner flank of the larger. Canescens is chiefly remarkable 

 for its enormous variation in form; in a series of about 

 forty males which I have before me, there is a regular suc- 

 cession proceeding without break from large males with 

 large heads, wider behind the eyes and wider than the pro- 

 thorax, the latter being much wider than long and narrowed 

 strongly behind, down to small males having very small 

 quadrate heads, narrower than the prothorax and not wider 

 behind the eyes, the prothorax being quadrate with the 

 sides parallel. The eyes in the large specimens are com- 

 paratively small and are far in advance of the hind angles, 

 but in the series as the head decreases in size the eye re- 

 mains the same, so that in the small specimens it appears 

 relatively very large and is at only its own length from the 

 posterior angles. These variations are not perceptible in a. 

 series of forty males of seminitens. 



