298 THE CANADIAN ENTOMOLOGIST. 



satisfactory form, and I have been unable to find easily seen characters 

 in all cases — partly because of the extreme resemblance in form among 

 certain genera, and partly on account of the wide variation in colour 

 shown by a few species precluding much use of this in a table. In part, 

 I have followed the " Classification," while in other places I have used 

 more readily perceived characters, which, while not in themselves of true 

 generic value, will nevertheless allow the species here treated to be 

 properly placed. The interpretation of specific characters is, in general, 

 after the " Revision of the CoccinellidK of the United States," by Mr. 

 Crotch, although he has not tabulated most of them. Scymnus is omitted 

 for the present. 



A word of caution is necessary to beginners. Some of the species 

 are very closely allied, and often so variable in colour, especially as re- 

 gards the greater or less development of the elytral spots, that they may 

 prove extremely puzzling, and in order to avoid mistakes the tables and 

 descriptions, which have been made fuller than in preceding papers of 

 this series, should be carefully studied. The considerable number of 

 figures offered should also prove an aid to accurate work. 



The species known from our region may be placed in their approxi- 

 mate genera by use of the following key : 

 A. Body pubescent. 



Antennae reaching base of thorax ; body oblong-oval. . . Coccidula. 



Antennae scarcely as long as the head ; body nearly hemis- 

 pherical Scymnus. 



AA. Body glabrous, base of antennte covered by a frontal plate, thorax 

 very small ; upper surface black, elytra each with one red 

 spot Chilocorus. 



AAA. Body glabrous, base of antennae exposed, thorax of moderate 

 size. 



b. Form oblong-oval or elongate, ventral lines absent or nearly 

 so. 



c. Elytra with sutural and discoidal black stripe Ncemia. 



cc. Elytra spotted. 



d. Thorax distincdy margined at base Megilla. 



dd. Thorax not margined at base. 



Small (.13 in.). Elytra each with eight spots,* 



sometimes confluent Anisostida. 



Larger (.20 — .30 in.). Elytra with not more than 

 six spots* on each Hippodamia. 



*The common sutural spots excluded. 



