Any attempt to discuss at length the difficult and thorny question of nomenclature would be entirely out of place in an elementary book on fossil plants, but there are certain important points to which it may be well to draw attention. When a student enters the field of independent research, he is usually but imperfectly acquainted with the principles of nomenclature which should be followed in palaeontological work. After losing himself in a maze of endless synonyms and confused terminology, he recognises the desirability of adopting some definite and consistent plan in his method of naming genera and species. It is extremely probable that whatever system is made use of, it will be called in question by some critics as not being in strict conformity with accepted rules. The opportunities for criticism in matters relating to nomenclature are particularly numerous, and the critic who may be but imperfectly familiar with the subject-matter of a scientific work is not slow to avail himself of some supposed eccentricity on the part of the author in the manner of terminology. The true value of work may be obscured by laying too much emphasis on the imperfections of a somewhat heterodox nomenclature. On the other hand good systematic work is often seriously spoilt by a want of attention to generally accepted rules in naming and defining species. It is essential that those who take up systematic research should pay attention to the necessary though secondary question of technical description. [Sidenote: RULES FOR NOMENCLATURE.] In inventing a new generic or specific name, it is well to adhere to some definite plan as regards the form or termination of the words used. To deal with this subject in detail, or to recapitulate a series of rules as to the best method of constructing names whether descriptive or personal, would take us beyond the limits of a single chapter. The student should refer for guidance to such recognised rules as those drawn up by the late Mr Strickland and others at the instance of the British Association[158]. It is not infrequently the case that the same generic name has been applied to a fossil and to a recent species. Such a double use of the same term should always be avoided as likely to lead to confusion, and as tending to admit a divorce between botany and palaeobotany. In the course of describing a collection of fossil species, various problems are bound to present themselves as regards the best method of dealing with certain generic or specific names. A few general suggestions may prove of use to those who are likely to be confronted with the intricacies of scientific and pseudoscientific terminology.