The last or lowest class is the _Fishes_, in which province Cuvier has himself been the great systematist, and has therefore had to devise many new terms. Many of these are of Greek or Latin origin, and can be anglicized by the analogies already pointed out, as _Chondropterygians_, _Malacopterygians_, _Lophobranchs_, _Plectognaths_, _Gymnodonts_, _Scleroderms_. _Discoboles_ and _Apodes_ may be English as well as French. There are other cases in which the author has formed the names of Families, either by forming a word in _ides_ from the name of a genus, as _Gadoides_, _Gobiöides_, or by gallicizing the Latin name of the genus, as _Salmones_ from _Salmo_, _Clupes_ from _Clupea_, _Ésoces_ from _Esox_, _Cyprins_ from _Cyprinus_. In these cases Agassiz's favourite form of names for families of fishes has led English writers to use the words _Gadoids_, _Gobioids_, _Salmonoids_, _Clupeoids_, _Lucioids_ (for _Ésoces_), _Cyprinoids_, &c. There is a taint of hybridism in this termination, but it is attended with this advantage, that it has begun to be characteristic of the nomenclature of family groups in the class _Pisces_. One of the orders of fishes, co-ordinate with the Chondropterygians and the Lophobranchs, is termed _Osseux_ by Cuvier. It appears hardly worth while to invent a substantive word for this, when _Bony Fishes_ is so simple a phrase, and may readily be understood as a technical name of a systematic order. The Mollusks are the next Class; and these are divided into _Cephallopods_, _Gasteropods_, and the like. The Gasteropods are _Nudibranchs_, _Inferobranchs_, {336} _Tectibranchs,_ _Pectinibranchs_, _Scutibranchs_, and _Cyclobranchs_. In framing most of these terms Cuvier has made hybrids by a combination of a Latin word with _branchiæ_ which is the Greek name for the gills of a fish; and has thus avoided loading the memory with words of an origin not obvious to most naturalists, as terms derived from the Greek would have been. Another division of the Gasteropods is _Pulmonés_, which we must make _Pulmonians_. In like manner the subdivisions of the Pectinibranchs are the _Trochoidans_ and _Buccinoidans_, (_Trochoïdes_, _Buccinoïdes)_. The _Acéphales_, another order of Mollusks, may be _Acephals_ in English. After these comes the third grand division, _Articulated Animals_, and these are _Annelidans_, _Crustaceans,_ _Arachnidans_, and _Insects_. I shall not dwell upon the names of these, as the form of English words which is to be selected must be sufficiently obvious from the preceding examples.