447] COLORS OF TIGER BEETLES— SIIELFORD 53 



Minnesota, Kansas, Nebraska, South Dakota, Colorado, Utah, Wyom- 

 ing, and New ilesico, but are very rare in eastern localities. Mr. 

 C. A. Frost secured one bluish black individual in Massachusetts. The 

 black forms of C. tranquebarica are recorded from a single locality 

 in California. No black forms occur in the localities where black 

 forms of other species occur though blackish green forms occur in the 

 Pacific States and blackish brown, in the Gulf States. Likewise there is 

 no correlation between geographic conditions and green forms. Scutel- 

 laris is green on the Atlantic coast, purpurea in the central and north- 

 ern great plains, tranquebarica on the coasts and coastal mountains. 



Exclusive of black forms which have just been discussed the geo- 

 graphic variation of colors in the species belonging to the tranquebarica 

 group, may be stated as follows: Geographic variations in color are 

 of special interest in the case of C. scutcllaris; I note green forms pre- 

 dominating in all specimens in the Atlantic Coast and Gulf States. 

 Bluish retlections characterize these as a rule, particularly in some 

 localities where occasional blue forms occur (Fig. 470 a). 



In Texas along the northeastern border near Oklahoma forms 

 occur with a decided golden cast which in series in some localities range 

 from bluish green through green with golden cast to flame red like 

 figure 554, plate XXIX ; north of this flame red predominates. Forms 

 with flame red eh'tra and green or blue thorax occur west to the Rio 

 Grande, occupying a triangular area with its apex just north of the 

 Black Hills and eastern point near Topeka, Kansas. Points a short 

 distance west of the Missouri River such as Topeka, Kansas, and Su- 

 perior, Nebraska, show great variation in marking and all intermedi- 

 ate color conditions between the forms with flame red elytra and those 

 of tlie dull brown and wine color occurring to the east and north of 

 the ilissouri River. The most brilliant wine colors occur between the 

 Mississippi and Jlissouri Rivers and in Manitoba; near Chicago 

 the brilliant wine colors are not usual, but greenish browns and green- 

 ish individuals are common. There appears to be no close correlation 

 between the distribution of these colors and any mapped distribution 

 of factors. 



C. purpurea is very variable ; figures 471 a, 472 show color varie- 

 ties of this species. In general among the groups in which tlic mark- 

 ings are withdrawn from the margin, the forms with the n[)per part 

 of the elytron reddish and its margins green are most widely distrib- 

 uted, extending almost throughout the range of the species except the 

 Pacific coast specimens which are golden green (Puget Sound, 10 ft.). / 

 The eastern forms are of the typical red elytroned type. In the entire "/ 

 ^Mississippi Basin, Great Plains, and Salt Lake Valley tliis is mixed 

 with green and black fonns, the latter two predominating in the west- 



