854 MR. w. BATESoif ON THE [Dec. 3, 



two black spots (see figs. 19-24), while in the spotted forms the 

 thorax is generally black with some lighter colour at the periphery 

 and not rarely in the middle line. 



Considering the ground-colour of the elytra there are thus two 

 chief kinds, red and greenish grey. The majority can at once be 

 referred to one or other of these two. Nevertheless there are 

 intermediate colours forming an unbroken series or transition 

 from the one to the other. Such a series is represented in 

 figs. 1-6. Starting from the bright red kind (fig. 1) and passing 

 through a duller red (fig. 2) a neutral buff (fig. 3) is reached. 

 This buff is almost exactly intermediate between the red group 

 and the greenish grey. The next stages in the transition are 

 yellow (fig, 4), yellowish green, and greenish grey (fig. 6). 



Taking spotted males alone the bright reds are by far the 

 commonest, the duller reds are the next commonest, the buff are 

 very rare, while yellows and greenish together make up a fair 

 group. As to the relative frequency of these yellows and greens, 

 the data are unreliable. The total nujuber belonging to these 

 classes was small, and it is not possible to sort them among 

 themselves with any strictness. I am satisfied that the yellows 

 are more common than the buffs, and the spotted greenish greys 

 are probably less common than the yellows ; but of this I am not 

 sure. In the Table given at the end I have united them. 



Of striped males almost all are greenish grey. Eeds and 

 yellows occur, but are exceedingly rare. The whole number of 

 striped specimens with a ground-colour other than greenish grey 

 is so small that it is not possible to judge the frequency of the 

 respective colours, I attempted for some time to distinguish 

 different shades of the greens according to the degree of yellow. 

 But while certain of the striped kinds are obviously yellow and 

 others are obviously yellowish green, it was not found possible to 

 sort consistently the yellowish greens from the greens with less 

 yellow, so this attempt was abandoned. 



With a view to determining the nature of the colouring-matters, 

 an examination of some specimens was very kindly made by 

 Dr. H, C, Sorby, The material sent to him consisted of a few of 

 the reds and a few of the greenish form separately killed and pre- 

 served in alcohol. Dr. Sorby informs me that the red pigment is 

 slowly dissolved out by alcohol and carbon bisulphide, and when 

 in solution in the latter is of exactly the same character as the 

 similar pigment of the common Lady-bird (C bipunctata). After 

 long action to dissolve out all the pigment of the elytra, the red 

 form is left of a yellow colour, exactly like that which is assumed 

 also by the greenish kind. Dr. Sorby therefore conjectures that 

 the reds differ from the others mainly on account of the develop- 

 ment of the red pigment which is not found in the others. It is 

 therefore possible that the ground-colours intermediate between 

 the red and the greenish may be due in some measure to a differ- 

 ence in the amount of red pigment ; but it seems likely that in the 



