458 Lord Rothsehild on Arctiinee prom: 
wider in proportion to the length (?, length of fore wing 
22°5 mm., width 12°5mm.; 3, length 15 mm., width 8°5mm.), 
and the costa near the base is produced into a lappet-like con- 
vex projection ; the hind wings are large with apex produced 
into a point, Nor small and round as in the @; the colour is 
salmon-pink, entirely opaque, being densely scaled. @ de- 
scribed, Fonte Boa, Amazons, Sept. 1906 (G. M. Klages 
coll.).] 
1 g caught. 
4. Robinsonia mossi, sp. n. 
3. Pectus white; palpi, frons, and vertex yellow ; 
patagia buff; rest of thorax and abdomen pure white. 
Fore wing semihyaline white, nervures whitish grey, costa 
and terminal fifth of wing sooty mouse-grey ; hind wings 
semihyaline white. 
Length of fore wing 18 mm. ; expanse 40 mm. 
1 ¢ type caught. 
5. Robinsonia rockstonia, Schaus. 
Robinsonia rockstonia, Schaus, Proc. U.S. Nat. Mus. vol. xxix. p. 206 
(1906) (Essequibo, British Guiana). 
1 S caught. 
6. Robinsonia dewitzi, Gundl. 
Robinsonia dewitzi, Gundlach, Contr. Entom. Cuba Lepid. 1. p. 265 
(1881) (Cuba). 
8 3 b,1 ¢ caught. 
7. Idalus neja, Schaus. 
Idalus neja, Schaus, Proc, U.S. Nat. Mus. vol. xxix. p. 208 (1906) 
(St. Jean de Maroni). 
This insect shows great variation in size ; the majority 
from the Guianas are small, but a few equal in size the 
Brazilian specimens, which appear to be mostly large. 
Length of fore wing, ¢: St. Jean de Maroni (smallest), 
18 mm., expanse 41 mm. ; Para (largest), 23 mm., expanse 
53 mm. . 
The undescribed ? is much larger, and differs.from the ¢ 
in the much broader, more brightly coloured, and much 
more rounded fore wings, and in the larger and more 
rounded hind wings. 
4 8 8,1 2 caught. 
