72 ILLIXOIS BIOLOGICAL MOXOGRAPHS [466 



PLATE I 



Explanation of Plate 



Figure i. Cross section of the adult elytron of C. lepida, showing the re- 

 lation of lack of pigment to interlamellar spaces. The portion at the right is 

 through a pigmented area and that at the left through an unpigmented area. PCU, 

 primary cuticula, unpigmented ; PCP, primary cuticula, pigmented ; SC, secondary 

 cuticula. The portion under the unpigmented areas is divided into layers sepa- 

 rated by air-filled spaces above which small canals project into the layer above; 

 under the pigmented part the cuticula is in clear layers with no spaces between. 

 The air spaces in the cuticula under the unpigmented portion are probably the 

 cause of the appearance resembling white pigment in the unpigmented areas. 



Figures 2-9. Showing the relation of the markings and tracheae in Cicindela. 

 The tracheae present are from left to right costa (Co) (see Fig. 21), the subcosta 

 (S), the radius (R), the media (M), and the cubitus (Cu). The anal cannot ordi- 

 narily be demonstrated in dried elytra. The drawings were made with a camera 

 lucida. The figures indicate a number of unpigmented areas which are in the 

 form of cross bands which may be broken by the pigment lying in the lines of 

 the tracheae ; the letters A, B, and C indicate the unpigmented stripes to fall be- 

 tween the tracheae. 



Fig. 2. C. regalis Dej. (Africa) ; 3, interrupta Fabr. (Africa) ; 4, inter- 

 rupta Fabr. (Africa) ; 5, dongalerisis Klg. (N. Africa) ; 6, vigintiguttata Herbst. 

 (India) ; 7, compressicomis Boh. (Africa) ; 8, compressicornis Boh. (Africa) ; 9, 

 discrepans Walk. (Ceylon). 



