COLOR CHANGES IN ' DYNASTES TITYRUS 



437 



it seemed important to find out more about this remarkable 

 exception. 



As ordinarily seen, the beetles are very dark red or black 

 on all the lower surfaces, and on the limbs and the horns and in 

 fact on all the top of the head and the thorax where the horns 

 occur, but with abundant yellowish 'hairs;' the same is true of 

 both sexes. But the rest of the thorax posterior to the horn 



Fig. 2 Photograph of living female Dynastes tityrus, showing form of head 

 and thorax and distribution of dark spots on the light colored elytra. 



region and the wing covers or elytra are not dark but very light 

 yellowish. This yellowish color is homogeneous on the thorax 

 posterior to the black horns, or horn region, but on the elytra 

 there are many spots of dark red which may be nearly black. 

 These spots are roughly in rows and differ in each specimen in 

 size, number and arrangement, but tend to run in lengthwise 

 rows. The spots are both large and small, the larger com- 

 pounded of several smaller more or less fused. Many of the 

 spots have a marked concentric arrangement of dark circles 

 about lighter centers. 



