Hesperia Gnidus, _Fabr._--Pap. Endymion, _Cramer_, Pl. 224, C, D,
(Male,) E, F, (Fem).--Erycina Gnidus, _Godart_; _Stoll’s Supp._ Pl. 4,
fig. 5, A, (Cater), 5, B, (Chrysalis).
The genus Helicopis was proposed by Fabricius in his _Systema
Glossatarum_, and he refers to the species above mentioned as one
of its typical forms. Although its characters are sufficiently
distinctive, it was long confounded with other groups to which it has
little relation. It belongs to that section of the diurnal lepidoptera
in which the caterpillars are short and depressed, having some
resemblance to an _oniscus_, whence they are called onisciform. The
palpi are rather long and slender, and the terminal joint is nearly
naked or free from scales. In Helicopis the antennæ terminate in a
slightly curved club: the anterior legs are much shorter than the
others and clothed with hairs; hinder margin of the anterior wings
convex and entire, the corresponding margin of the posterior with six
linear tails, the central one much longer than the rest; discoidal cell
of the posterior wings open behind; claws very minute. Caterpillar
thickly clothed with soft hairs, the chrysalis suspended by the tail,
and having a band round the middle.
The best known and most common species of this genus is _H. Cupido_,
which is rather smaller than _H. Gnidus_. The former is commonly named
the Golden-spot, and the latter the Silver-spot Butterfly. The wings
of _H. Gnidus_, in the male, are white on both sides, with a slight
tinge of yellow at the base, and the outer margin black. At the hinder
extremity of the secondary wings there is a row of narrow white marks,
which is double at the anal angle; tails black on both sides, the two
longest ones tipped with white. The upper wings beneath have a white
line dividing the black border behind the middle, and the under pair
are ornamented with twenty-one silvery spots, three of which at either
extremity are elongated and placed on a white ground, while the rest
are insulated and on a ferruginous ground; all of them edged with
black. The female is larger than the sex just described, and differs in
having a larger fulvous space at the base of the wings, and in having
it bounded externally on the under side of the upper pair by a wide
black patch; the greater part of the surface of the hinder wings is
black, and the posterior row of white crescents is simple: body white,
the thorax yellow; antennæ black, ringed with white.
The caterpillar is white, and clothed with long hairs of the same
colour; the head yellow, surmounted by a tuft of red hairs. It feeds on
the leaves of the passion-flower, and changes into a brown chrysalis,
which has a tuft of red hairs at the head and tail.
This species, as well as _H. Cupido_, is a native of Surinam.