THE CANADIAN ENTOMOLOGIST. 153 



I 



to render their detection, even when swept into the net, a matter of some 

 uncertainty. The two genera are thus distinguished : — 



Antennas serrate from the sixth joint Exema. 



Antennal serrations beginning before the sixth joint Chla?nys. 



Exema, Lac. 



A small black, rough beetle, about .10 in. long, often variegated with 



very small yellow spots or even with the head and prothorax almost 



entirely yellow. The legs are usually more or less yellow, the antennae 



entirely so. The Canadian E. dispar, Lac, is considered a variety of 



E. conspersa, Mann. 



Chlamys, Knoch. 



Represented by C. plicata, Fabr. , a larger insect than the preceding, 

 and of shorter, more robust form. The tuberosities of the upper surface 

 are very pronounced, the colour more or less 

 metallic brown or black, legs black. The 

 variety polycocca is that in which the tubercles 

 are more distinctly separated and not aggre- 

 gated into the form of ridges as in typical Fig. 14. 

 plicata. Length, .16 in. Fig. 14 represents the larva (a) and its 



curious sack. 



Tribe VL — Cryptocephalini. 



Form robust, more or less cylindrical, and sometimes even 

 approaching globularity. Elytra rather short, leaving the tip of the 

 abdomen exposed, net tuberculate, striato-punctate. Antennse usually 

 long and slender. Colours usually arranged in a variegated pattern, 

 taking on various combinations of spots or stripes, which are sometimes 

 very inconstant ; occasionally a species is found which is unicolorous. 

 The genera are thus separated in the " Classification " : — 

 A. Claws appendiculate (/. ^., with a square dilatation at base; small 

 species). 



Form robust, rounded Monachus. 



Form more elongate, cylindrical Diachus. 



AA. Claws simple (mostly larger species). 



b. Prothorax not margined at base, crenulate, 



Frontedgeof prothoracicflanks sinuous or \.oo\k\&dL.Bassareus. 



Front edge of prothoracic flanks straight . . . Cryptocephalus. 



bb. Prothorax margined at base, not crenulate; presternum feebly 



channelled Pachybrachys. 



