Among the generally accepted canons of nomenclature is the rule that if a description includes two or more species, it shall be valid for neither as against subsequent authors who discriminate the forms properly.

While all of us may not be willing to push this rule to its limit and reject the first name altogether, it certainly is a wholesome restriction against a custom which has prevailed in some quarters, notably in France, of making loose and indefinite descriptions, waiting until some more careful writer has separated one of the forms as distinct and named it, and then declaring that the latter was the species really intended by the indefinite description, thus at one stroke of the pen creating a synonym and finding a new species to be named.