14 Mr. A. G. Butler on Heterocerous Lepidoptera 



collection in 1880 : in all its important characters it 

 agrees with the original ligure of M. qffinis in Guerin's 

 'Magazin de Zoologie'; but the ground colour of the 

 primaries and the thorax are chalky-white, sparsely 

 irrorated with hiovm, whereas in the figure they are 

 represented as almost wholly brown : that the latter 

 coloration is incorrect (notwithstanding that Blanchard 

 has exaggerated it) is shown by Feisthamel's description, 

 which says — " Le dessus des premieres ailes d'un gris 

 blanc"; and again, " Le corselet est du meme ton que 

 les ailes superieures" ; so that there can be no question 

 that the example obtained by us is the true M. affinis, 

 and consequently that the insect identified with the 

 latter in Chili, and here named by me M. rivularis, is a 

 perfectly distinct and new species. 



Ormiscodes, Blanch. 

 21. Ormiscodes socialis. 



? . Bomhyx socialis, Feisthamel, Mag. de Zool. 2e ser. 



pi. 22, fig. 1 (1839). 

 Catoccphala socialis, Blanchard, in Gay's 'Chili,' Zool. 



7, p. 63, n. 1 (1854). 

 Dirphia ancjidifcra, Walker, Cat. Lep. Het. 6, p. 1368, 



n. 23 (1855). 



Four pairs. 



The male is smaller than the female, has more red on 

 the secondaries, and the antennae broadly pectinated ; 

 the ground colour varies considerably. 



" Description of larva. Full-fed, 1|- inches long ; 

 above beautiful pale green ; beneath pale red in many 

 specimens, in others green; a spiracular line, prominent 

 and pearly-white, edged with reddish brown ; each seg- 

 ment with stellate tufts of prickles, except the head and 

 18th ; those on the 2nd and 3rd longest ; eight on each 

 segment, excepting the 7th to the 10th, which have but 

 six, the row beneath the spiracular line on the other 

 segments being missing in these ; the prickles sting like 

 nettles. Full-fed in November. Does not congregate in 

 masses like gregarious larvae, but a large number are 

 often found scattered on the same branch. Food-plant, 

 ' Peumo ' {Crytocaria peanuts). 



