HIPPODAMIA. 



21 



HEREDITY. 



The three females in table 3 with unknown mates show clearly enough 

 that the presence or absence of spots 1 and 2 is inheritable. No. 453 had 

 the transverse band broader than usual and its progeny show the inherit- 

 ance of this condition, for in some of the offspring- the mother was exceeded 

 in this respect and none of them show the slightest tendency to the separa- 

 tion of the component parts. The heredity of spots 1 and 2 is segregative, 

 with a few intergrades. The shortness of the pedigrees leaves the ques- 

 tion of dominance unsettled. 



TABLE 3. Heredity in Hippodamia glacialis. 



3046. Hippodamia convergent Guerin. 



Distribution: North America. 



This is a wide-ranging species which is highly variable. For reasons 

 given later I have thought it best to reduce to the status of varieties several 

 of its derivatives which have received specific names. The variation (fig. 

 11) is strikingly parallel to that in Hippodamia septempunctata and to a 

 less degree to that in Adonia varieyata. The varieties of these two Euro- 

 pean species have been well studied and named. This is not the case with 

 the American H. convergens. I have indicated the correspondence of these 

 varieties by the sign of equivalence ( - ) used by mathematicians. The 

 correlation of pronotal and elytral patterns is low enough to make it desir- 

 able to treat them separately. 



Types of Patterns in Elytral Spots. 



Spots , 1, 2, 3, 4, 5, 6. Typical. 



Spots A +3 + 1, 4 + 5, 6, va>-. quinquesignata Kirby. 



Spots J +3 + 1, 4 + 5, 6, with pronotal discal spots, var. puncticollis Casey. 



Spots i -|- 3 -|- 1, 2, 4 -f- 5, 6, H. septemmaculata var. continue/,. 



Spots | + 3 + 1, 2, 4, 5, 6. 



Spots -f-3, 1, 2, 4 + 5, 6, var. caseyi (new variety) - >A. variegatavar. ustiilata Weise. 



O H. tredecimpunctata var. contorta Weise. 

 This common variety is generally called lecontei Mulsant, the description of which 



calls for a pattern quite different, which is given below. This variety is so well 



known that it seems best to rename it. 

 Var. dejecta (new variety). Formula as in var. caseyi, but spot 1 small and 1 -(- 3 



much less heavily pigmented. 



Because of its interesting relation with var. caseyi, discussed later, this variety is 

 given a name. 



