of the Amazon Valley. 315 
at the base of the hind wings beneath ; at least the thirteen specimens 
now before me from the Amazons and Guatemala have all this mark 
of distinction. 
82. Agerenia velutina, n. sp. 
3. Expanse 3” 2’. Closely resembling the figure given in Doubleday 
& Hewitson’s ‘Genera Diurn. Lep.’ pl. 10. fig. 2, as representing Ageronia 
Arete of Boisduval. Boisduval’s 4. Arete, however, according to the de- 
scription published by M. Lucas as cited under the preceding species, is 
identical with Cramer’s P. Arethusa. The figure given by Messrs. Double- 
day & Hewitson, in the absence of a description and figure of the under 
side, is insufficient to enable one to identify the species. A. velutina 
differs from it in the absence of the light-brown hue of the costal border 
of the hind wing. 
Ageronia velutina G differs in the form of the wings from 4. Arethusa 3, 
the outer borders being more bowed outwards, and the costa of the fore 
wing being regularly arched, without indentation opposite the end of the 
cell. Connected with this absence of indentation is a striking difference 
in the neuration of the wing—the upper and middle disco-cellulars, as 
well as the portion of the subcostal between the origin of the second 
branch and the end of the cell, being very oblique, instead of deflected 
almost in a transverse direction as in 4. Arethusa; the lower disco- 
cellular also joins the median close to its terminal fork, instead of at a 
great distance from it as in 4A. Arethusa. The whole under surface of the 
wings in 4. velutina has a rich, silky, changing bluish gloss, and the red 
basal spots of the hind wing are only two in number. 
Found at various places on the Upper and Lower Amazons, in the 
same situations as A. Arethusa, A. Feronia, &c. I did not meet with 
the female. 
Genus Diponis (Hubn.), Westw. in D, & H. Gen. p. 407. 
The larvee of this genus, according to the figure given by Bois- 
duval in the Crochard edition of Cuvier’s ‘ Régne Animal,’ resemble 
those of Ageronia in having setigerous lobes proceeding from many 
of the abdominal segments ; in the long cephalic spines they resemble 
the larvee of the whole group of Nymphalide to which Epicalia, 
Ageronia, Callithea, and so forth belong. In the neuration of the 
wings Didons agrees with many genera of this same group. I do 
not see, therefore, why the genus should be withdrawn from the 
true Nymphalide and placed with others in a separate family 
(Eurytelide or Biblide), as many lepidopterists have done, following 
the example of Dr. Boisduval. The rounded shape of the wings and 
inflated base of the costal nervure cannot be signs of great divergence 
when so much variety of shape exists in the family, and so many 
