413] COLORS OF TIGER BEETLES— SHELFORD 19 



of the majiings or iinpigmented areas, of such a character as to suggest 

 a direct pliysiologieal relation between the two. In the specimens in 

 which the tracheae are unusually arranged there is no effect on the color 

 pattern or variation on that suggests a direct relation between the two. 

 Nor is there any connection between the oxygen supply from the 

 tracheae and the pigment. And as the blood sinuses and tracheae are 

 for the most part coincident, I see no reason for relating the blood 

 supply to these characters. The folding of the elytron in the pupa is 

 apparently not related to the cross bands. It accordingly appears that 

 the relation of pigment formation in the elytron to structure is not 

 directly causal, at the present stage in the evolution of the groups but 

 is one belonging to the general structural organization, hereditary in 

 character. 



THE COLOR PATTERN PLAN 



The pattern of the Cicindelae is analyzable into the areas or tend- 

 encies sho^^Ti in figures 42 to 49, plate V. Figure 42 shows the full 

 number of dark and light longitudinal stripes. The light stripes are 

 labeled a,A,B.C ; a is not usually distinct. Very often it is absent as in 

 figures 3, 4, 6, and 11, but sometimes appears to be present without A 

 as in figures 5 and 13, plate I and II. It is often present and partially 

 separated from A in an Australian species (Pigs. 50 and 51, PI. VI) 

 only. This Australian species is the basis for figure 42. More often it 

 is joined with A (Fig. 43), and not recognized separately (Fig. 52). 

 Figure 44 indicates a tendency to double lines between the tracheae 

 suggested by an African species (Fig. 53, also 57 and 7 and 8). Figures 

 54 and 56 show the longitudinal stripes partially represented. 



Figue 45 shows the full niunber of cross bands rarely complete 

 numbered 1 to 7 ; but perhaps best represented in figures 57 and 59 to 

 63 where they occur broken two spots. Bands 5 and 6 occur nearly 

 complete oftener than 2 and 3 (Figs. 57 and 75). Figure 46 shows the 

 type in which 2 and 3, and 5 and 6 are fused. This is almost a duplicate 

 of the pattern of an .\frieau species, figure 58, but also well represented 

 bj- figures 73 and 74. Figure 47 shows a common type, cross bauds 

 5 and 6 being separate but the more anterior ones being reduced at the 

 anal side of the elytron. Figure 48 shows all the possible spots which 

 resulted from the superposition of the longitudinal stripes and cross 

 bauds. There are 19 of these, of which 11 occur in an Indian species 

 (Fig. 62). 



Figure 49 shows the spots or elements from which the characteristic 

 patterns of the group are made up. This pattern should be compared 

 with figures 31 to 33, plate III. which show that individual variations 

 follow the rule of the entire group. The usual pattern of C. tranque- 



