That this group of insects is one of the most interesting amongst the Lepidoptera, and at the same time exceedingly difficult, with respect to its natural relations, cannot be denied. Modern authors, Mr. Swainson observes, have been unfortunate in their location of this group, of course alluding to its being placed by Latreille in the family Hesperiidæ. Mr. Swainson, however, is not less unfortunate in his introduction of it into the family Papilionidæ, with which the structure of the fore legs is said peculiarly to rank it. This character, nevertheless, together with its day-flying habits and brilliant colours, are the only points in which an affinity can be traced between the Papilionidæ and Uraniidæ. But the structure of the hind legs (having spurs in the middle, as well as at the tips of the tibiæ), and of the nerves of the wings, antennæ, and palpi, all exhibit a very slight degree of relationship with Papilio. Mr. Swainson has, indeed, endeavoured to make the affinity more evident by introducing Papilio Curius, Fabr. as a subgenus (Leptocircus) in the genus Leilus (or Urania), but the relationship between these is of the slightest and most unsatisfactory kind. Mr. Newman has suggested another view of the affinities of this group. In his sketch of the circular distribution of the Lepidoptera,[[5]] he has introduced into the Butterfly circle, the genera Coronis and Urania, the last forming the connecting link with the Geometridæ, by Leach's genus Ourapteryx, or the Swallow-tail Moth. The whole structure of the latter insect indicates, however, most clearly that the relation is but an analogical one. Had, indeed, the observations of M. Sganzin,[[6]] relative to the transformations of Urania Rhipheus been confirmed, this would certainly have been its more appropriate locality, its caterpillar being said by him to be a semi-looper, and its chrysalis to be naked, suspended by the tail, and girt round the centre. But the elaborate memoir of Mr. MacLeay,[[7]] upon the habits and changes of Urania Fernandinæ, prove most clearly that the larva closely resembles that of Agarista;[[8]] and that the pupa, as in that genus, is inclosed in a cocoon. Now this latter character exists in some species of Hesperia. In these, however, the chrysalis is still attached by its tail. Mr. MacLeay does not mention whether such is the case in Urania; but since his return from Cuba he has had the kindness to shew me the cocoon, and to inform me that the chrysalis is loose. This character, therefore, with the entire structure of the imago, removes it from the Diurnal Lepidoptera, and associates it most satisfactorily with the Hesperi-sphinges of Latreille, especially Agarista and Coronis, which last is very near Urania Lunus. Thus the situation proposed for these insects by Latreille, between Hesperia and Agarista, &c. is found to be most fortunate; Mr. Swainson himself admitting a relationship with the Hesperiidæ, by calling them the "Hesperian" type of the Papilionidæ. They also appear to have some relation with Erebus. The original specimen here figured is stated by Mr. Drury to have been in the possession of Captain May, of Hammersmith, when the drawing was made. It is now in all probability destroyed, and cannot be traced.
THECLA PAN.
Plate [XXIII]. fig. 3, 4.
Order: Lepidoptera. Section: Diurna. Family: Lycænidæ, Leach.
Genus. Thecla, Fabr. (Syst. Gloss.) Polyommatus p. Latr. Papilio (Pleb. rural.), Linn. &c.
Thecla Pan. Alis fuscis bicaudatis; subtus fuscescentibus, ocellis duobus anguli ani, externo nigro iride rufâ. (Expans. Alar. 1 unc. 3 lin.)
Syn. Papilio (Pleb. rur.) Pan, Drury, App. vol. 2.
Habitat: Jamaica.
Upper Side. Antennæ black. Thorax, abdomen, and wings dark brown, or dark hair-coloured; the latter being furnished with two small tails like hairs, the extremities being white.
Under Side. Palpi white. Breast greyish. Wings nearly the same colour as on the upper side. The posterior having two eyes on each at the abdominal corners; one being black with a red iris, the other grey and faint; above them is a small indented white line, pointing to a spot of the same colour placed at the middle of the anterior edge.