116 RHOPALOCERA. 
mari similis, sed major et alarum pagina inferiore spe maculis et lineis irregularibus indistincte fuscis 
notata. 
Hab. Mexico1?%, Cuernavaca and Putla (coll. Oberthiir *), Oaxaca (Fenochio); GuatE- 
MALA, Chuacus, San Bernardo, Quirigua, below Alotenango, Cerro Zunil, Retalhuleu 
(Ff. D. G. & O. S.); Nicaragua, Chontales (Belt); Panama. 
The nearest ally of I. polyphemus is the South-Brazilian WV. laertes, no representative 
of this group of the genus being known anywhere in the intermediate region. From 
M. laertes (M. epistrophis, Hiibn., being probably not specifically distinct) its northern 
congener differs at first sight in the purity of the white of its colour, the Brazilian 
insect always having a delicate greenish tint pervading its wings; and there are other 
differences. Both forms seem liable to a considerable amount of individual variation. 
The dark apex of the primaries in MV. polyphemus in some individuals is altogether 
absent ; in others it is a strong feature; the dark mark at the end of the cell varies 
from an evanescent stripe to a prominent streak; the submarginal row of spots on the 
secondaries likewise varies from a mere indication to a series of conspicuous marks. 
None of these variations seems associated with any particular locality. On the under- 
side great variation exists in the size of the ocelli. In Mexican specimens those of the 
secondaries are usually smaller than. in Guatemalan examples; and in the former that 
beyond the end of the cell is often absent. 
Morpho tuna, described by Mr. Butler from a Mexican specimen, which is now in our 
possession, is a large male example with the markings more than usually developed ; 
but our Mexican specimens gradually lead up from an almost spotless individual to 
this extreme form, and we consequently do not see how the distinctness of MW. luna can 
be maintained. We arrive at this conclusion, notwithstanding Mr. Butler’s strongly 
expressed opinion to the contrary*. It may be remarked that Mr. Butler has never 
told us what the distinctive characters of his species are to distinguish it from 
M. polyphemus ; for in the first instance he seems to have compared it with MV. laertes2, 
which is not really to the point. As to the difference of locality alluded to by him on 
the authority of M. Oberthiir, we do not attach much importance to the statement ; 
Cuernavaca and Putla are places in Mexico at no great distance apart, and are situated 
on the same side of the mountain chain. | 
In Guatemala WM. polyphemus has a very wide range, being found in suitable localities 
in the forest districts bordering both oceans, and it also extends its range to an elevation 
of quite 4000 feet above the sea. These butterflies usually fly at a considerable height 
from the ground amongst the forest-trees; but on one occasion we met with a number 
of individuals which were flying low through the little village of San Bernado, in the 
valley of the Motagua river, and we easily captured several specimens. 
The flight of UM. polyphemus is, like that of other Morphos, rather rapid and 
undulating. 
