We have elsewhere pointed out, as one of the peculiar distinctions of forms and groups pre-eminently typical, that their geographic distribution is invariably wide, and generally universal; and that this is one of the reasons why certain forms are found both in Europe, America, India, and Australia. This was said of Birds, and the remark is even more applicable when we look to insects. We accordingly find, that the typical species of the genus now under consideration, not only spread themselves over all Europe and Africa, but extend to the Indian islands on one side, and over the whole of America on the other, without offering more than a sectional variation of character. It is uncertain, however, whether any species occur in Australia; for the European type seems to be represented there by the sub-genus _Erina_. The genus, _collectively_, is a rasorial type, representing the family _Satyridæ_ among the _Papiliones_,--_Parnassius_ among the _Papilionidæ_,--and the _Paconidæ_ among Birds. Pol. Cassius is one of the most common species of Brazil, where we found it frequenting similar situations, and possessing the same habits, as the ordinary Blues of England. The analysis bestowed upon this group, convinces us that _Pithecops, H._ is but a section of this sub-genus. The upper figure represents the male, the lower the female: both are enlarged. The connecting species between _Polyommatus_ and _Lycæna_ are _Helle_, Hub. _Lametia_, and _Boeticus_. * * * * * * [Illustration: ERINA _pulchella_.] ERINA pulchella. _Buff-spotted Blue._ ---- Family, Ericinidæ. Sub-fam., Theclinæ. _Sw._ Genus, Polyommatus. _Lat._ Sub-genus, Erina. _Sw._ SUB-GENERIC CHARACTER. Wings obtuse, very entire: palpi covered only with compact scales, the last joint lengthened, slender, and very naked. Club of the antennæ short, broad, and spatulate. Colour, dark blue, spotted beneath. _Typical._ Hesp. Erinus. _Fab._ _Aberrant._ Lycæna ignita. _Leach._ ---- SPECIFIC CHARACTER. _Wings above brown, glossed with blue; anterior with a discoid fulvous spot; beneath white: posterior pair with three black dots in the middle._ Mus. Brit. Nost. ----