northwards into the Upper Saskatchewan valley as far as the southern limit of trees, there being much less intermixture with Canadian forms than might be expected. Then crossing the Sierra Nevada, and going overland to Oregon, I was able to trace the gradual passage of the Californian insect-fauna into the Oregonian, with some Canadian forms; and by passing up the Columbia river to Wallula, here as well as at Reno in Nevada, to perceive the great differences between the fauna of the Pacific slope and that of the plains and deserts of the Central province.

In briefly reviewing the different orders of insects, other than Coleoptera,which have been so fully elaborated by Dr. LeConte, and certain groups of Crustacea, we will begin with the Hymenoptera, and point out a few characteristics distinguishing the Central from the Pacific provinces. In 1865 and 1866 a large number of Coloradian fossorial Hymenoptera passed under the writer's hands, Mr. Cresson having previously described from this material a large number of Coloradian Hymenoptera of all families. The richness of the hymenopterous fauna of Colorado struck me, and I was impressed with its distinctness from that of the Eastern States. I have seen few of these forms from California. Among the family of ants (Formicida), there is one form characteristic of the plains which does not occur on the Pacific slope. This is the Pogonomyrmex occidentalis (Cress). I have seen its large hills at Brookville, Kansas, and observed them in Colorado and Utah and in Reno, at the base of the Sierra Nevada, but not west of that point. It ranges, according to Mayer, south into New Mexico, and San Luis valley, Colorado. Its nest forming large elevations in cleared spaces sometimes six or eight feet in diameter, is one of the characteristic sights on the plains.

Among the Lepidoptera, family Bombycide, there are several forms peculiar to the central district, notably the genus Dirphia (Coloracia), Euleucophæus, Gloveria (Mesistesoma), Hemileuca Juno and Hera, and Platysamia gloverii. The family is feebly represented in the Central province, but richly so by numerous species on the Pacific slope, which do not appear east of the Sierra Nevada.

The Phalanidæ, or geometric moths, are richly developed in the Pacific province, and but poorly in the Central province, owing to the absence of deciduous trees; of those found in the latter some occur west of the Sierra Nevada, and some are peculiar to the plains and Rocky mountains.

Of the Orthopera there is a large number of species peculiar to the plains which I did not observe in the Pacific States; of these, Caloptenus spretus is thoroughly characteristic of the Central province. It does not occur in the Pacific and only breeds temporarily in the Eastern province, and its natural limits define well those of the province itself. It ranges up to lat. 53° N. on the North Saskatchewan and south to Southern Utah and Colorado. The exact limits of its distribution are given in the First Annual Report of the U. S. Entomological Commission.

Of a

While we are still ignorant of the distribution of insect life between the hundredth meridian and the Pacific ocean, there seems good reason, from what we do know, and from the great differences in the flora, and the soil and climate, especially the rainfall east and west of the Sierra Nevada, to regard this lofty range as the general point of separation defining two grand zoological provinces. Many groups of insects abounding west of the mountains do not occur east, except in isolated cases. number of Myriopods found on the Pacific coast none occur east, and so of the Arachnida so far as known, and Dr. Thorell, who has worked up some of the spiders of Colorado, was struck by the general similarity of some forms to those occurring in the plateau of North-eastern Asia. Among the insects there are a few Pacific forms which closely resemble European species, and which are not represented east of the Sierra Nevada. It should be borne in mind, however, that the Sierra Nevada does not present an absolute barrier, as a considerable number of species occur on each side of it, and it is well known that the Rocky Mountains are but a slight barrier to the distribution of the animals on either side, the fauna of Colorado, Northern Utah, Wyoming, Montana and Idaho being quite homogeneous, and the fauna of these Territories the same on each side of the high mountain ranges traversing them.

Among the fresh-water Crustacea the Astaci of the Pacific slope, as is well known, belong to the European genus Astacus, those east of the Sierra Nevada to the genus Cambarus, which is so richly developed in the Eastern provinces, especially in the Mississippi valley.

The distribution of the fresh-water Phyllopoda is of peculiar interest. The family Apodide is restricted to the Central province: none are found in the Mississippi valley, and none in Cali

fornia. Of the four species of Apus all inhabit the Central province; Apus æqualis lives on the plains of the Rocky mountains, and also at Matamoras, in Mexico. It is a curious fact that Apus lucasanus Pack., not only occurs at Cape St. Lucas, Lower California, but is also an abundant species at Ellis, Kansas. This is a parallel case to the presence of certain birds at Cape St. Lucas which, as observed by Prof. Baird, belong to the Central rather than to the Pacific province. Of the genus Lepidurus there are two forms (L. couesii and L. bilobatus) characterizing the plains. L. couesii occurs in Northern Montana, and is allied to a recently described Lepidurus from Archangel, Russia, according to Lilljeborg.

The eastern limits of the Central province extend to near the 97th meridian in Kansas and Nebraska, according to the writer's observations.

-:0:

THE REPORT OF THE COMMITTEE OF THE AMERICAN ASSOCIATION OF 1876 ON BIOLOGICAL NO

MENCLATURE.

BY E. D. COPE.

́N the year 1842 the British Association for the Advancement of Science took into consideration the question of zoological nomenclature, and through a committee made a report, which embodies a series of recommendations in the form of rules. In 1863 another committee of the British Association revised these rules and reprinted them with various additional recommendations. This report was republished in this country with a few additional suggestive notes by Prof. A. E. Verrill, in 1869.1 Since that date the question has been discussed by the American entomologists Scudder, Edwards and LeConte.

The rules issued at the earlier periods above mentioned dealt largely with etymological and literary questions, while admitting in general terms the necessity of observing the law of priority of date. The energy of some of the resurrectionists of obsolete works in bringing to light old names, however, soon drew attention to the importance of ascertaining the real nature of priority of date; and the close coincidence of date of some modern publications, has brought up the question from another side. The 1 Amer. Jour. Sci. and Arts, July.

entomologists first began to handle the subject critically, the most practical article with which I am acquainted being that of W. H. Edwards.1

In order to establish a basis of definite action in this matter, the American Association for the Advancement of Science at its meeting in Buffalo, in 1876, appointed a committee "to obtain an expression of opinion from the working naturalists of America in regard to the nature of a set of rules for facilitating the decision of questions relating to nomenclature," etc. The committee consisted of Capt. Wm. H. Dall, of the U. S. Coast Survey, and the results of his work are now given. To my own mind the method pursued by Capt. Dall was excellent, and the results are very satisfactory as displaying a degree of unanimity among American naturalists so complete as to constitute their opinions, as embodied in Capt. Dall's report, a set of rules which no one can safely disregard on the one hand, or hesitate to follow on the other.

Capt. Dall's prefatory remarks are as follows:

In accordance with the understanding and resolutions of the Section, by which this duty devolved upon him, your Reporter prepared a circular which was printed under the supervision of the permanent secretary and circulated by the Smithsonian Institution, a copy of which is appended to this report.

The circular was sent to all who, within the last five years, might be included under the designation of publishing naturalists, and of whom the address could be obtained. This list included about eighty-five names, from a number of which (for various) reasons) a response was hardly anticipated. They were used, however, in order that the fullest opportunity might be afforded to all those who might desire to express an opinion.

The responses received to date (August 14,1877), are forty-five in number. While a few honored names, to whose views all would attribute due weight, are not on the list, yet it includes most of those whose contributions are familiar in the Proceedings of American Scientific societies, and an unquestionable majority of the best working naturalists of the country. The views of several of those from whom no response was received, have been incorporated in the appendix by means of citations from their works.

The queries contained in the circular relate chiefly to certain points, concerning which a diversity of opinion has existed among naturalists; the general principles of nomenclature not being in question. The responses are divided into affirmative, negative 1 Canadian Entomologist, February, 1873.

and doubtful, while in individual cases some queries received no response. The answers classified as doubtful, comprise those which by their tenor indicated that the purport of the particular query had not been clearly understood, and some in which the person replying avowed his inability to express a preference for any one of several modes of proceeding.

The gratifying unanimity which is exhibited in the responses to certain of the more important and clearly defined questions at issue, indicates that a thorough study of the more complicated questions by the light of the general principles of nomenclature, would result in a practical agreement on the part of American naturalists in relation to nearly all the matters in debate.

It is evident from the responses of naturalists, that their opinion is generally adverse to any attempt to limit, by arbitrary rules, the right of publication in the most convenient direction, and against any statute of limitations in regard to scientific names. This seems to be in accord with the principles of justice, equity and general usage in nomenclature, though at times inconvenient in its results. It may be confidently expected that the majority of authors, when their attention has been drawn to it will, for their own interest as well as that of science, avoid in future publications, the methods (or want of method) which in the remote. past sowed so many germs of present difficulty.

The circular with replies is preceded by the following note by Capt. Dall:

NOTE.

The question with which the working naturalist is most frequently brought face to face-and in the decision of which so much trouble is experienced and such diverse opinions are elicited -are chiefly those which involve the right of any one of several names to be considered as properly proposed and entitled to take precedence of others, provided its priority in time of application be established.

The rule that names (otherwise unexceptionable) which are prior in date, are to be accepted in nomenclature to the exclusion of all others, is conceded by all naturalists.

The rules recommended by the Committee on Nomenclature of the British Association for the Advancement of Science, have been generally adopted; though in certain details they are regarded by many naturalists as defective. Nevertheless they have largely contributed to that uniformity which is so desirable in the matter of nomenclature.

It has been thought that a similar recommendation on the part of the American Association might reach many who are not conversant with the British rules and tend to produce in the works of the rising generation of American naturalists a similarly beneficial agreement.