RIIIPICERIDAE. 175 



This genus contains but one species, P. Edwardi^i Lee, found 

 in California. It is a small broadly oval depressed insect, with 

 the sides of the thorax exi)latiale, and the elytra vaguely sulcate. 

 The elytra of the male are luleous, of the female piceous. 



Fam. XL— RHIPICERIDAE. 



Mentum quadrate, corneous; ligula small, not prominent; 

 palpi o-joiuted. 



Maxillae exposed at tlic base; usually witli but one lobe; 

 palpi 4-jointed. 



Antennae inserted before and inside of the eyes, under 

 ridges, 11-jointed (in our genera), serrate in the females, fre- 

 quently flabellate in the nuiles. 



Head prominent; eyes round; epistoma not distinct; 

 labrura indistinct; mandibles large, stout and prominent in 

 Sandalus, small in Zenoa. 



Prothorax with the side pieces not separate; coxal cavi- 

 ties large, transverse, open behind; prosternum not pro- 

 longed. 



Mesosternum short, oblique, flat; side pieces attaining the 

 coxoe. 



Metasternum short in Sandalus, moderate in Zenoa; side 

 pieces wide in the first, narrow in the second; epimera large 

 in Sandalus, not visible in Zenoa. 



Elytra covering the abdomen ; epii)leura^ extending to 

 the apex. 



Abdomen with five (in our genera) free ventral segment's. 



Anterior and middle coxas conical, prominent, the former 

 with large trochantins ; posterior cox^e transverse, dilated 

 into a small plate partly covering the thighs. 



Legs moderate, tibias with small terminal spurs; tarsi ;")- 

 jointed; claws simple; onycliium long, hairy. 



A fiunily containing a small number of species, found on plants; 

 Sandalus especially affecting various cedars; it is represented 

 both in the Atlantic and Pacific districts; Zenoa contains but 

 one species in the Atlantic district. 



Tarsi not lolxxl ; antcnnre modprately loiis^, serrate. Zenoa. 



Tarsi lolled ; anteniicT sliort (9 serrate, %, llabellate). Sandalus. 



These two genera indicate different tribes, distinguished, as 

 above stated, by the form of the side pieces of the metathorax. 



