swimming of the typical Portunidæ, the Oceanic Crabs of the tropics, as the long leaps of the Flying Squirrels and the Petauri bear to the sustained flight of a bird.
None of our native Crabs are "at the top of the tree" in the swimming profession; their efforts, even those of the best of them (and there is a good deal of difference in the species even of the true Portuni), are awkward bunglings, when compared with the freedom and fleetness of those I have seen in the Caribbean sea, and among the Gulf weed, in the tropical Atlantic, which shoot through the water almost like a fish, with the feet on the side that happens to be the front all tucked close up, and those on the opposite side stretched away behind, so as to "hold no water," as a seaman would say, and thus offer no impediment to the way. Our species are obliged to keep their pair of sculls continually working while they swim; a series of laborious efforts just sufficient to counteract the force of gravity; and the see-saw motion of the bent and flattened joints of the oar-feet is so much like that of a fiddler's elbow, as to have given rise to a very widely adopted appellation of these Crabs, among our marine populace.
An old male of the Velvet Fiddler is a striking and handsome Crab. His body generally is clothed with a short velvety pile of a pale brown or drab hue, from beneath which here and there shines out the glossy deep black shell, especially where rubbed, as at the edges. The feet, particularly the plates of the oars, are conspicuously striped with black; the large and formidable claws are marked with bright scarlet and
