‘Watching a Broad-claw beneath a stone close to the side of my tank, I noticed that his long antennae were continually flirted about; these are doubtless sensitive organs of touch, or some analogous sense, which inform the animal of the presence, and perhaps of the nature, of objects within reach. At the same time I remarked that the outer foot-jaws (pedipalps) were employed alternately in making casts, being thrown out deliberately, but without intermission, and drawn in, exactly in the manner of the fringed hand of a Barnacle, of which both the organ and the action strongly reminded me. I looked at this more closely with the aid of a lens: each foot-jaw formed a perfect spoon of hairs, which at every cast expanded and partly closed. That you may understand this better, I must say that the foot-jaw resembles a sickle in form, being composed of five joints, of which the last four are curved like the blade of that implement. Each of these joints is set along its inner edge with a row of parallel bristles, of which those of the last joint arch out in a semicircle, continuing the curve of the limb; the rest of the bristles are curved parallel or concentrical with these, but diminish in length as they recede downwards. It will be seen, therefore, that when the joints of the foot-jaw are thrown out, approaching to a straight line, the curved hairs are made to diverge; but as the cast is made they resume their parallelism, and sweep in, as with a net, the atoms of the embraced water[48].’ All this description may be verified from a spirit specimen, if the foot-jaws be carefully removed. And the examination with the lens will also show that these hairs are plumose, that is, set with smaller hair, like the barbs of a feather. At this point we may conveniently take leave of the Stalk-eyed, and pass on to the Sessile-eyed, Crustacea. Leaving the Cuma´cea out of the question, we have two Sub-orders from which to choose our subjects--the Amphip´oda and the Isop´oda--conveniently Englished, Am´phipods and I´sopods. We learn from Mr. Stebbing[49] that ‘the Amphip´oda, which are common in fresh as well as in salt water, were so named by the French naturalist Latreille, as having feet extending in all directions, their limbs at the same time having much diversity of form, in correspondence with diversity of function. The Isop´oda, or equalfooted animals, besides being found both in fresh and salt water, have more decidedly than the Amphip´oda extended their range to the dry land. The name was invented by Latreille in ignorance of the great number of species, since investigated, in which the feet are strikingly unlike and unequal. Nevertheless, the name may stand, just as a rose remains a rose even when it is not rose-coloured.’ These last two sentences must be borne in mind, for they throw great light on a subject that may give us some trouble--the question of priority in nomenclature.