78 ILLINOIS BIOLOGICAL MONOGRAPHS [472 



PLATE IV 



Figures 34-38- Showing the relation of the tracheae to pigmentation of the 

 elytra in Carabidae and Dytiscidae. 



Explanation of Plate 



Fig. 34. Omophron sp. (N.A.), showing suggestions of transverse bands num- 

 bered to correspond with figures 66 and 67 and a tendency for white markings 

 between the bands to lie between the tracheae; 35, Bembidium versicolor Lee. 

 (Illinois), showing the unpigmented areas in the lines with the tracheae; 36, 

 unknown carabid (Amazon), showing the pigmented areas in the lines of the 

 tracheae; 37,Nebia complanata Linn. (Europe), showing a tendency to lines over 

 the tracheae and between them; 38, Hydacticus stagnalis Fabr. (Illinois), show- 

 ing double lines; 39, Laccophilus maculosus Say, showing the transverse bands 

 and suggestion of double unpigmented lines with the tracheae in the pigmented 

 areas (see Fig. 18) ; 40, Agabus taeniolatus Harr. (Illinois), showing trachea in 

 the unpigmented areas with a suggestion of double lines; 41, Hydroporus undu- 

 latus Say (Illinois), showing the cross bands — a suggestion of all those commonly 

 present in Cicindela. 



