ARGES (Goldfuss) is the Paradoxides bimucronatus of Murchison.
AltGULUS, a genus of Entomostracous Crustacea, belonging to the section Pacilepoda. There is but one species of this genus, the A. foliaceus. This little creature is not unknown to fishermen, as it is frequently found parasitic upon various kinds of fish. It was first , described by Baker in his Employment for the Microscope,' in 1753, under the name of The Louse of the Carp and Banstickle or Prickleback.' It 'is about the tenth of an inch in length, and is I almost as broad as it is long. The head is in the form of a circnlar shaped shield. The antenna) are short, thick, and two-jointed. Instead of a second pair of foot-jaws it has a pair of circular or disk-shaped suckers, by means of which it attaches itself to the animals on which it is parasitic. These suckers are admirably constructed for their use. Four muscles are attached to the base of each of these organs, and extend up by the aides. By this arrangement the creature can make use of these organs, by exhausting the air in the same way as in cupping-glasses, to fasten itself, and also by relaxing the muscles, to walk, when it wishes to change its position. These little creatures are nearly transparent, or of a slightly greenish hue, so that its internal organisation can be readily seen by means of the microscope by transmitted light. The body is marked on both aides by a series of ramifications of a dark colour. The female is larger than the male, and is distinguished, in addition to the ovary, by a black mark on each lobe of the abdomen.
The Argulus is found upon various fresh-water fishes. It is most frequently met with near London on the Stickleback, hut it has been noticed as occurring on the Carp, the Roach, the Trout, the Pike, the Rudd, and even upon the tadpole of the common Frog. It seems to abound especially when fish are in ill health.
Although mostly found upon fish it frequently haves them, and coitus freely about in the water. Fish have an instinctive kiiowledge of thew creatures as their enemy, and it is amusing to watch in a basin of water the efforts which the stickleback will milk.) to avoid its minute persecutor ; but the effort.' of the fish are in vain, for it is opposed to a creature which has the power of darting through water with such rapidity that it is almost impossible to follow it with the naked eye. The females deposit their eggs from 400 to 1500 in number on atones or other solid bodice. They are laid aide by side in rows and glued together. They are hatched in about 35 days, and the young resemble their parents to a greater extent than is the case with many of the forma of Entomostroce. The best account, with figures and anatomy, of this parasite, is given in Dr. Baird's ' history of the British Entemostraca,' published by the Ray Society. Ni-. Yarrell has given a figure of it in the second volume of his ' British Fishes.'