The geological term Trias, lately introduced to designate the group consisting of the three members (Bunter Sandstein, Muschelkalk, and Keuper) becomes improper if, as some geologists hold, two of these members cannot be separated.
Objections resembling those which apply to numerical designations of species, apply to other cases of fixed series: for instance, when it has been proposed to mark the species by altering the termination of the genus. Thus Adanson[45], denoting a genus by the name Fonna (Lychnidea), conceived he might mark five of its species by altering the last syllable, Fonna, Fonna-e, Fonna-i, Fonna-o, Fonna-u; then others by Fonna-ba, Fonna-ka, and so on. This would be liable to the same evils which have been noticed as belonging to the numerical method[46].
[45] Pref. clxxvi.
[46] In like manner the names assigned by Mr. Rickman to the successive of styles of Gothic architecture in England,—Early English, Decorated, and Perpendicular,—cannot be replaced by numerical designations, First Pointed, Second Pointed, Third Pointed. For—besides that he who first distinctly establishes classes has the right of naming them, and that Mr. Rickman’s names are really appropriate and significant—these new names would confound all meaning of language. We should not be able to divide Early English, or Decorated, or Perpendicular into sub-styles;—for who could talk of First Second Pointed and Second Second Pointed; and what should we call that pointed style—the Transition from the Norman—which precedes the First Pointed?
Aphorism XVII.
In any classificatory science names including more than two steps of the classification may be employed if it be found convenient.
Linnæus, in his canons for botanical nomenclature (Art. 212), says that the names of the class and the order are to be mute, while the names of the Genus and Species are sonorous. And accordingly the names 311 of plants (and the same is true of animals) have in common practice been binary only, consisting of a generic and a specific name. The class and the order have not been admitted to form part of the appellation of the species. Indeed it is easy to see that a name, which must be identical in so many instances as that of an Order would be, would be felt as superfluous and burthensome. Accordingly, Linnæus makes it one of his maxims[47], that the name of the Class and Order must not be expressed but understood, and hence, he says, Royen, who took Lilium for the name of a Class, rightly rejected this word as a generic name, and substituted Lirium with the Greek termination.
[47] Phil. Bot. s. 215.
Yet we must not too peremptorily assume such maxims as these to be universal for all classificatory sciences. It is very possible that it may be found advisable to use three terms, that of Order, Genus, and Species in designating minerals, as is done in Mohs’s nomenclature, for example, Rhombohedral Calc Haloide, Paratomous Hal Baryte.
It is possible also that it may be found useful in the same science (Mineralogy) to mark some of the steps of classification by the termination. Thus it has been proposed to confine the termination ite to the Order Silicides of Naumann, as Apophyllite, Stilbite, Leucite, &c., and to use names of different form in other orders, as Talc Spar for Brennerite, Pyramidal Titanium Oxide for Octahedrite. Some such method appears to be the most likely to give us a tolerable mineralogical nomenclature.