264 



KELLOGG AND BELL 



the modal subclass (modal in both) shows in the smaller series a 

 frequency of 13.5 per cent, less than in the larger series. 



"Aberrations." A considerable entomological literature 

 cataloguing and describing " aberrations" has grownup, especi- 

 ally in connection with systematic lepidopterology. As an 

 example of what may be done in this kind of refined systematic 

 work the following 74 easily, briefly and definitely describable 

 aberrations contained in a series of 1,782 individuals, being the 

 combined two series of 1,031 and 751 just discussed, of Hippo- 

 damia convergens, all taken at one time in one locality (a cir- 

 cular area 12 feet in diameter), are presented. In this list 

 Class D in each of the preceding series, composed of indi- 

 viduals possessing more than the 12 modal elytral spots is 

 analyzed into its subclasses (which was not done in the previous 

 discussion), but the subclasses of Class A (based on the differ- 

 ences in size of the exactly 12 spots present and distinct) are 

 not taken into account. The aberrations (or variation classes) 

 catalogued are based wholly on numbers of elytral spots and the 

 varying combinations (varying by suppression or addition of 

 particular spots) of spots which compose the number. 



1. Hippodamia convergens. "Twelve spotted lady-bird," 

 typical of the species description, each wing-cover being 

 marked by 6 distinct and separate spots. 



2. H. convergens; aberr. A r " Eleven-spotted lady-bird," 

 spot 3 1 being absent. 



3. H. convergens; 



aberr. A 2 . " Eleven-spotted lady-bird,'* 



spot i 1 being absent. 



4. H. convergens; aberr. A 3 . 

 spot 2 1 being absent. 



5. H. convergens; aberr. A 4 . 

 spot 3 r being absent. 



6. H. convergens; aberr. A 5 . 

 spot 2 r being absent. 



7. H. convergens; aberr. A 6 . 

 spots 4 r and 5 r coalescing. 



8. H. convergens; aberr. A 7 . 

 spots 5 1 and 6 1 coalescing. 



9. H. convergens; aberr. A 8 . 

 pots 4 1 and 5 1 coalescing. 



" Eleven-spotted lady-bird," 

 "Eleven-spotted lady-bird," 

 "Eleven-spotted lady-bird," 

 "Eleven-spotted lady-bird," 

 " Eleven-spotted lady-bird," 

 "Eleven-spotted lady-bird," 



