The visitor's way now lies out of the northern gallery, by its eastern door, near which he should notice a remarkable sun fish, of a bulky and squat appearance. Having regained the first, or most northerly room of the great eastern zoological gallery, the visitor should turn to the south, examining the table cases of this gallery as he returns through its spacious rooms. All the table cases of this gallery, with the exception of a few small side tables, are covered with the vast varieties of the SHELLS of molluscous or soft animals. These shells, scattered over no less than forty-nine tables, represent the architectural capacities of the great order of soft-bodied animals, only inferior in rank, in Cuvier's "Animal Kingdom," to the Vertebrate animals. Upon the first table, before which the visitor will find himself (49), are some interesting specimens of the well-known Cuttle fish, exhibiting its varieties, including the common cuttle fish found upon our coasts; those which have the power of secreting a dark fluid, and those from India, whose ink-bags furnish artists with that valuable brown called sepia. Here, too, are the skeletons of the slender loligos, or sea leaves, known also as sea-pens; and the crozier shell. Upon the next six tables (48-53), proceeding southward, are the varieties of the Oyster, the Mussel, and beautiful Mother-of-pearl shells. But hence the visitor will probably proceed rapidly to the south; inasmuch as the varieties of the mussel family, including the Chinese pearl mussel and Scotch pearl mussel, the borers, the club shell, and the cockle family, are not generally interesting; but he will probably linger for a few moments near the pond mussels placed upon some of the tables (38-41). The tables numbered from 24 to 30 are covered with the varieties of hard shells, which, however, present no points of interest to the general visitor, who may at once pass on to the varieties of the Nautilus and Argonaut, (tables 23, 24). And here, too, we must entreat the visitor to forget the poetic history of the inhabitants of those beautiful shells, and learn that the extended arms of the nautilus are used only to clasp its shell; that it has no sails of any kind. The varieties of the paper nautilus, or argonaut, are the most delicate and beautiful. The next table (22) displays the shell of the curious carrier, that embodies all kinds of foreign substances with its shell; the slipper shell, and the rose bud. Upon the next table (21) are the Screws; the curious ladder shells from China; and upon table 20, are the varieties of fresh water Clubs. The next two tables (18, 19) display some curious and beautiful shells, including Venus's ear, the pagoda shell, and varieties of Snails, including the apple snails. Proceeding on his southern way, the visitor should pause to notice the ear shells, placed upon tables 18, 17, including the beautiful rainbow; the button shells, the rainbow