The Origin of the Markings of Caterpillars. 255 



THE GENUS PTEROGON, BOISD. 48 



Although I am acquainted with only a small 

 portion of the developmental history of a single 

 species of this genus, I will here proceed to record 

 this fragment, since, taken in connection with two 

 other species, it appears to me sufficient to deter- 

 mine, at least broadly, the direction of develop- 

 ment which this genus has taken. 



green, the two areas being separated by a white subdorsal line 

 bordered above with brown. The dorsal line is feebly repre- 

 sented. Macroglossa Belts, Cram., N. India (loc. cit. PL XC., Fig. 

 6), is figured with the ground-colour deep indigo ; a conspicuous 

 white subdorsal, and a yellow spiracular line is present; on 

 the side of each segment, between the two lines mentioned, there 

 is a large red spot with a yellow nucleus (? eye-spots), the spots 

 decreasing in size towards the head and tail ; these probably 

 confer upon this species some special protective advantage. 

 Macroglossa Pyrrhosticta, Butler, China and Japan (loc. cit. PL 

 XC., Fig. 8), is greenish-white with dorsal andsubdorsal lines, and 

 seven dark oblique stripes along the sides, below the subdorsal 

 line. Of the foregoing species Hemaris Hyas appears to be in 

 the same phyletic stage as M. Stellatarum and M. Croatica, 

 &c., whilst M. Pyrrhosticta is probably, together with M. Cory, 

 thus and M. Gilia, in another and more advanced stage, which 

 is also passed through by Lophura Hyas in the course of its 

 ontogenetic development. This last species (adult) and M. 

 Belts may represent phyletic stages still further advanced. 

 Caliomma Pluto, Walk., of which the caterpillar is figured by 

 Burmeister (loc. cit. PL XIII., Fig. i), appears to be a case of 

 special protective resemblance to a twig or branch of its food- 

 plant. Figured also by Chavannes ; Bull. Soc. Vadoise des 

 Sci. Nat, Dec. 6th 1854. R.M.]. 



46 [Genus Pterogon, Boisd., = Proserpinus and Lophura 

 (part). Butler, loc. cit. p. 632. The species above treated of 

 = Proserpinus (Enothera, Fabr. R.M.] 



