Publisher's Synopsis
Excerpt from The Sympoda
When the question arises of arranging the families in a natural order, one would probably think precedence appropriate to those which retain the most primitive characters. Among these would be the most complete segmentation of the body and the fullest equip ment of the segments with their several pairs of appendages. On the first account the families with a distinct telson should stand before those without one. But when the second point is also con sidered, we find the full complement of five pairs of pleopods combined with entire want of a distinct telson, or in one case with a telson of the smallest type. All other families with the telson distinct have a diminished number of pleopods, varying from three pairs to none. These differences refer only to the male sex, because, so far as at present known, all the females with singular unanimity dispense with pleopods altogether. In some families, however, the males are in this respect like the females. The provision of exopods or swimming branches on the permopods in the two sexes has its uses for systematic arrangement. But while in the majority of families the adult males have these branches well developed on the first four pair of peraeopods, the females are never so well provided, having at most exopods well developed on the first three pairs and a rudiment on the fourth. In both sexes the exopods may be limited to the first pair of peraeopods. For full advantage to be taken of these much-varying characteristics it is obviously important that both sexes should be observed. But, owing probably to the respective habits of these, it not unfrequently happens that new species have to be, or at any rate are, founded on specimens of a single sex, so that the characters of the other sex have to be guessed at or left out of count. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.
