With respect to range, the results arrived at have no particular interest, for the species are not sufficiently numerous; and, what is still more adverse, the genera, with unimportant exceptions, range over the world; so that there is no scale of differences, and it cannot be said that these two regions differ in their genera, and these two only in their species. In all the following remarks, I have trusted exclusively to my own specific identification; and have rejected all assigned localities which appeared from any cause to be doubtful. Sessile cirripedes are found in every sea, from lat. 74° 18′ north to Cape Horn. The area included between the north point of the Philippine Archipelago and the south point of Australia, extending on the right hand to New Zealand, and on the left to Sumatra,--an area, which, though including two distinct Cirripedial regions, is small compared with the surface of the globe, yet includes a greater number of species, especially of peculiar species, than the whole rest of the known world. This is, probably, in chief part due to the broken nature of the land, affording diversified habitats, and to much of the coast being rocky. Cirripedes, from requiring to be attached, cannot live where the shores and adjoining bottom are sandy or muddy or formed of moving shingle; hence, no doubt, it arises, that there is such a remarkable contrast in the great number of the species inhabiting the bold rocky western coast of South America, and the few species living on the sloping, and often sandy or muddy or shingly, eastern shores of this continent. Hence, also, I believe, it is that not many species have been brought from India. Coral-reefs are not favorable to Cirripedes, consequently but few are known to inhabit the islands of the Pacific Ocean. Where Cirripedes can live, though the species in no district are numerous, the individuals abound in infinite numbers: I have walked over the coast-rocks of the Falkland and Chonos Islands, of Chile and Van Diemen's Land, fairly encrusted over wide spaces with a continuous layer of Cirripedes, consisting of only two or three species; in the same manner as may be observed on many parts of the shores of Great Britain, and, I believe, of North America.