OF THE AMAZON VALLEY 
519 
This species, which is the only Ithomia found in the Amazon region that might he 
considered a Bymenitis, is found only at Tabatinga, on the Peruvian frontier. It re- 
semhles much L Udessa (Hewitson, Exot. Butt. Ithomi , fig. 12.), a native of 8. E. Brazil 
but it is a little larger, and differs considerably in the hind-wing ncurationof the 6. In 
L Edessa there is a middle and an upper disco-cellular nervule, and the upper radial is 
only partially aborted ; indeed, the neuration is identical with that of 7. Virginia and 
I. Oriana; but in Nephele the approximation to Hymen it is is carried a step further; for 
the middle and upper disco-cellulars, as well as the upper radial, are all quite aborted, 
although the lower disco-cellular and radial are not attached to the subcostal. In the 9 
the middle disco-cellular joins the subcostal, and there is no trace of an upper radial. 
Genus Melin^a, nov. genus. 
The species of this distinct group were placed by Doubleday in section 2 of the genus 
Mechanitis; but he failed to mention or misstated most of the principal characters of the 
section. The genus is nearest allied to Olyras and Thyridia; in fact, it approximate 
these much more closely than it does Mechanitis. From Olyras it diffen in the fore 
legs of the c?, in the palpi, and slightly in the wing-neurat ion ; from Thy rid i a also in 
the fore legs of the male, in the palpi, and in the antennae. The following are its principal 
characters. 
Palpi short, smoothly clothed with scales, and closely applied to the forehead; third 
joint not porrect as in Mechanitis and the allied genera. Antennae very long and slender. 
Eore legs of the <3 with the tibiae and tarsi more or less abbreviated, but never reduced 
to a rounded knob ; the tibia always shorter than the femur. Eore tarsi of the ? long, 
filiform, spines wide apart. Hind-wing costal widely separated from the subcostal in 
both sexes, in the tf long, reaching nearly the apex of the wing, in the 2 very short, 
terminating on the costa : the lower disco-cellular in both sexes straight, nearly in a line 
with the median nervure ; the median nervure, in fact, describes a gentle curve, the lower 
radial being placed as though it were a fourth median branch : the middle disco-cellular 
is at right angles with the lower, strongly angulated in its middle, and emitting a 
recurrent nervule : upper disco-cellular rather long, transverse, joining the subcostal at 
about one-half the length of the wing. 
The great resemblance in colours and markings between the species of Melinaa and 
those of Mechanitis has led to the confounding of the two genera; in other words, a 
relation of analogy has been mistaken for one of affinity, just as in the case of the two 
subfamilies Keliconinm and Danama. There is, however, as will be seen on comparing 
the characters of the two genera, a wide structural difference in the palpi, fore legs of 
the male, and neuration of the hind wings. Some species of Melincsa so nearly resemble 
species of Mechanitis, that they might easily be mistaken for them. The two analogous 
forms accompany each other ; but I think I found proof that they are not adapted one 
to the other, in the fact that the species of the two genera do not coincide in any locality 
on the Amazons, but vary and segregate races without any mutual specific similarity. 
They are very frequently accompanied by a Eelkonius assimilated to them in colours 
