52 EVOLUTION IN COLOR-PATTERN OF THE LADY-BEETLES. 



Var. A Mulsant. The sublateral spot of pronotum confluent with the central pattern 

 (see fig. 37). In a lot of 111 from Stony Lake, Michigan, 80 per cent were 

 of this variety, 10 per cent with a sublateral spot separate, and 10 per cent 

 transitional. 



Var. B Mulsant. Several of the black spots absent. One from Garland, Colorado. 

 Var. E Mulsant. The mark prolonged to level of spot 3. Rare. 



Subspecies of Oregon to California: Specimens from this region show 

 spot 3 + |, spot 2 absent, and 4 small. The pronotal pattern has an ad- 

 ditional lateral process cephalad of the usual one. 



3053. Hippodamia americana Crotch. 



Distribution: Lake Superior and Hudson Bay. 



The type specimen in the Leconte collection makes it clear that this 

 abused name belongs to a species closely allied to H. tredecimpunctata 

 rather than to specimens of a variety of H. 

 spuria. It is essentially a black-sutured, 

 usually vittate derivative of H. tredecim- 

 punctata (fig. 39). The specific rank must 

 be retained for the present because of the 

 lack of a large series. The great variation 

 in the few specimens known makes it possi- 

 ble that larger numbers from Lake Supe- 



, . T7 . FIG. 39. Variation in pronotal pattern in 



riOr might redUCe it tO a Variety Ot tl. ire- H. americana. a, from Hudson Hay: 

 . m1 , d, from Lake Superior. 



decimpunctata. The pronotum has the pig- 

 ment so extended that it generally conceals the characteristic lateral pro- 

 jection of H. tredecimpunctata. 



3051. Hippodamia parenthesis Say. 



Distribution: United States, except the southeastern States. 



Fitch has named a long series of forms, some of which are scarcely 

 worthy of recognition (see fig. 40). Being based on one character, two or 

 more of these forms are often embodied in one specimen. There is more 

 intergradation in this species than in the others of Hippodamia. 



Form tridentifrons Fitch. 



Three white spots on head confluent. Common. (See fig. 41.) 



Form permacrifrons Fitch. 



Three spots on head, separate and reduced. 



Form triangularis Fitch. 



White spot on pronotum, triangular instead of square. Rare. (See fig. 42.) 



Form lituricollis Fitch. 



Black pattern of pronotum much reduced, not touching caudal edge of pronotum and 

 "having a large black dot on each side confluent with it by a neck only one- 

 half as thick as the dot." This form is interesting as showing components 

 of the pattern similar to those in H. tredecimpunctata. 



Form albomaculata Fitch. 



White basal spots adjoining scutellar marks. 



