16 



EVOLUTION IN COLOR-PATTERN OF THE LADY-BEETLES. 



Genus MACRONAEMIA Casey. 

 3035. Macronaemia episcopalis Kirby. 

 Distribution: Western States and Canada. 



The pronotal pattern in a specimen from Assiniboin, Montana, and in another from 

 Wyoming is reduced to 6 spots. Otherwise it is relatively constant. 



Genus PARANAEMIA Casey. 

 303?. Paranaemia vittigera Mannerheim. 



Distribution: Colorado, New Mexico, Arizona, California, and New 

 Mexico. 



Shows very little significant variation. Casey believes those of Colorado and Arizona 

 to be more slender, but with similar coloration, and has called them P. similis. 



FIG. 3. Variation of the'elytral pattern of Megillii maculata. c=mode; a to </ from Shawnee, 

 Pennsylvania; h from Ohio and Texas. 



Genus MEGILLA Mulsant. 

 3036. Megilla maculata DeGeer. (Figs. 3, 4.) 

 Distribution: United States and Canada, except Pacific coast. 



This species is more constant than the other spotted Hippodamini (fig. 3), as indicated 

 by the following count of 321 individuals from Shawnee, Pennsylvania. 



Normal, 310. 



Form a. The elytral spot at 3/4 on the suture 



resolved to a spot on each elytron free 



from the suture; 4 individuals. 

 Form 6. 1 + scutellar mark; 2 individuals 



(fig. 3,/.) 

 Form c. An extra spot between 1, 2, and the 



scutellar mark; 1 individual (fig. 3, d) ; 



1 also seen at Cold Spring Harbor, New York. 

 Form d. 3 + 5; 1 individual (fig. 3, g); 1 also from Texas. 

 Form e. Spot 2 resolved into a larger internal and a smaller lateral spot (fig. 3, b). 



There was a case of a slight deposition of pigment along the vein between 1 



and 2 and in another between 4 and 6, in each case upon the right side only. Also 



one case of 2 + 3 on left side only. 

 Form /. Scutellar mark + 2. Not taken in the Shawnee lot, but 1 seen from Texas 



and 1 from Ohio (fig. 3, h). 



The typical species is found only in Cuba. It has but one continuous 

 area of black pigment upon the pronotum. The two subspecies following 

 may be entitled to specific rank. The decision must wait for more ex- 

 tended collection in the Southeastern States. 



FIG. 4. Variation of the pronotal pattern 

 of Megilla. maculata. 6=niode; a to c, 

 from Shawuee, Pennsylvania. 



