The identity of this species, it will hence appear, does not rest upon opinion or conjecture, and this circumstance must be deemed of no small importance in an enquiry of this nature. In the present instance it may be also added that this identity is essentially material to be considered, because there is another insect of the same tribe, the Papilio Laodocus of the same author, which assimilates so closely with it, that without due attention, the one might readily be confounded with the other. These two butterflies, however, although they appear so nearly allied, present characters which considered accurately, demonstrate very clearly that Fabricius was right in separating them. Fabricius adverting to this close affinity, observes, that in size and appearance Papilio Acamas agrees with Papilio Laodocus. The predominant colour of P. Acamas, he observes, is a dark or fuscous brown, much less inclining to black than P. Laodocus. The anterior wings in both species have a yellow transverse band: this band in P. Acamas extends from the anterior margin almost close to the posterior margin, and touches the posterior rib; in P. Laodocus this yellow band is abbreviated or shorter, of greater breadth, and placed more immediately towards the middle of the wing, the band in P. Acamas being situated rather nearer towards the exterior end of the wing. There is also a marginal series of yellow spots at the extremity of the anterior wings, the form of which is very singular, and affords a striking distinctive character of P. Acamas. There is also a characteristic difference observable in the markings of the posterior wings: in both species, on the upper as well as lower surface, those wings are elegantly marked with a distinct arch of red lunules, posterior to which is another of blue; beyond these in P. Acamas is a third series of lunules, rather larger than either of the former, the colour of which is bright yellow. There is a final or posterior arch of lunules in P. Laodocus, behind the two series of red and blue lunules, similar to those of P. Acamas, but they are smaller, and instead of yellow are white. And lastly, the body in P. Acamas is dark brown above and pale beneath: in P. Laodocus, on the contrary, the body beneath as well as above is black, with a longitudinal line each side the body. We have been thus minute in pointing out precisely the differences that prevail between these two Papiliones, from a persuasion that they might perhaps be otherwise confounded together, either as the same species, or as varieties of each other. There is assuredly a general approximation in the appearance of those two insects, although they prove so very distinct upon a close and attentive comparison. Papilio Acamas is a native of Jamaica: Papilio Laodocus of South America. A figure of P. Laodocus occurs in the work of Cramer, under the name of Papilio Glaucus. ------------------------------------------------------------------------ [Illustration: _19_