of the medulla with those of the spinal cord is illustrated, and the path is suggested (theory again) by which impressions received by the trigeminus and vagus may find their way through the longitudinal fasciculi and tractus intermedio-lateralis to the motor roots, especially of those nerves concerned in respiration.

We may also call particular attention to the chapters on the vagus, and on the auditory nucleus.

Among mammalia, the observations were for the most part confined to the sheep and the cat. A gap in comparative anatomy is therefore rather indicated than filled up.

In conclusion, we may state that the method of preparation employed in the investigation was essentially the one recommended by Clarke, and that the memoir has an especial feature in being illustrated by photo-lithographs. The author has also sent us specimens of the original photographs, some of which are excellent, but they have all suffered somewhat in the process of transference to the stone.

XLII. BRITISH ANNELIDS.

A CATALOGUE OF THE BRITISH NON-PARASITICAL WORMS, IN THE COLLECTION OF THE BRITISH MUSEUM. By George Johnston, M.D., Edinb. London: printed by order of the Trustees, 1865. pp. 365, 23 plates and 50 woodcuts.

SOME thirteen or fourteen years ago, it was known to many British Naturalists that the late Dr. Johnston was engaged on the compilation of a Catalogue of British Annelids, for the Trustees of the British Museum. For many years previously, Dr. Johnston had paid great attention to this subject, and the volumes of the "Magazine of Zoology and Botany," and the earlier ones of the "Annals and Magazine of Natural History," contain many valuable papers by him, giving descriptions of new, or little-known, genera and species, while a special supplement to the later Journal, published in January, 1846, was devoted to a list of the then known British Annelids, a list that, until within the last few years, when the General Dredging Committee of the British Association published a fuller one, was the only guide the English student had to this very puzzling group. It would appear that previous to Dr. Johnston's decease, the greater part of the Catalogue which we proceed to

notice was not only compiled, but printed. Why it should not have been published twelve years ago is a mystery to us. We perceive, however, from the preface, that "A Supplement, prepared by Dr. Baird, containing addenda, corrigenda, and a notice of additional species found since Dr. Johnston's death, with a complete index, have been added, to render the work more complete."

At the time when Dr. Johnston drew up this catalogue, there were few, besides himself, in this country who made any very special study of the Annelids. Nor although Savigny, Oersted, Grube, Audouin and Milne-Edwards had, to a considerable extent, reduced a chaotic mass of genera and species to something like order, was this to be wondered at; for at this present moment, although much additional work has been accomplished, the difficulties in the way of investigating these animals are nearly as great as ever. We purpose to consider by-andbye why this is the case, but in the first instance, will give a brief analysis of the contents of the book before us. At the outset, we take especial objection to the title of this volume. The division of the Annuloida (even supposing that we exclude from this group the Echinodermata) into parasitical and non-parasitical worms is such a clumsy and unnatural one, that it cannot for a moment be justified; bringing together, as it does, families in no way related to one another, and separating those which have undoubted affinities.

In

The first Order alluded to is that of Turbellaria. The enumeration of the British species, accompanied as it is by very brief and uncertain diagnoses, will be of little assistance to the collector. deed, even with the late researches of M. de Quatrefages, this order is shrouded in almost Egyptian darkness. A large number of the species here given are Dalyellian, and those who have had occasion to try to identify the new species in Sir Charles Dalyell's works well know how hopeless is the task, in spite of the beauty of many of the illustrations. The genus Stylus, which dates but from February in this year, is formed for the reception of four species described by Dalyell, in all of which the posterior end terminates in a cartilaginous style.

The second Order receives the name Bdellomorpha; but it is not that order as characterized by E. Blanchard, who formed it for the reception of the genus Malacobdella. It contains the genera, Octobothrium, Udonella, Capsala, and Nitzschia,* which would appear to

Dr. Johnston was generally most accurate in his spelling, and yet we find in one page the following varieties of spelling for this word:-Nitchia, Nitzchia, and Nitschia, none of them being correct. The latter is the spelling in the Index. Nitzsch lived until 1837.

be synonyms of Tristoma (and all of which belong to the Trematodes) and Malacobdella; which latter, while showing certain affinities in its development to the Trematodes, is, perhaps, better placed at the end of the Discophora. The third Order is that of the Bdellidea, which is synonymous with the Discophora of Grube. This, and the next order, that of the Oligochata, are now almost universally regarded as sub-orders of the Annulata. Here we have the various species of Pontobdella, Hirudo, and Glossiphonia, and in the appendix there are more copious details, and, in some cases, better descriptions than in the text. In the list of the British genera we notice the following instances of incorrect spelling: Trocheta for Trochetia, Hæmopsis for Hamopis, Glossophonia for Glossiphonia. Doubtless, further investigations will not only add many species to the genus Glossiphonia, but will also assign many of the present species as varieties of others. In the account of the Oligochata, there are many interesting details as to the habits and economy of the earth worms. The old controversy, as to the power of the common worm to reproduce lost parts is here renewed, and one can now look at the subject from a more impartial point of view than it was possible to do some fourteen years ago. Villa is the name of a new genus made for the reception of the Lumbricus ciliatus of Müller, which would appear to differ from Lumbricus in having the segments armed with setaceous bristles in four fascicles. According to Dalyell, it is constantly found lurking in the sand of the shore at about half-tide, from whence the head is protruded, waving to and fro. Grube is followed in placing Tomopteris in an order by itself, Gymnocopa. We are inclined to think Tomopteris founded on immature forms; but this question cannot be settled until something is known about its modes and forms of reproduction. No reference is made in the addenda to the various papers by Carpenter, Claparede, Pagenstecher, and others, on this genus.

We now come to the larger and more important portion of this work; the section which treats of the Annelida, the "Annulata appendiculata polychaeta" of Grube. An introduction of five pages treats of the various terms used in describing the genera and species. But these terms are, for the most part, very loose and inexact, whence one of the difficulties of this portion of descriptive Zoology has, we think, arisen. For example, what is an Antenna? what a Palpus? what a Tentaculum? how do these all differ from Cirri? and what are the so-called foot and its bristles, branches, and cirri?

How can one be sure, in comparing one description with another, how far they differ, and how far they agree, unless there be a fixed and definite nomenclature. Some years ago, in 1856, Professor Huxley attempted to introduce, among the Annelida, a modification of the system of nomenclature, proposed with so much success by MilneEdwards, among the Crustacea. But this system has not been adopted as it ought to have been, and even in the latest works on the Annelids, and in the very last papers descriptive of new species, we find the same old, we wish we could say antiquated, terms introduced. Every Annelid is composed of a certain number of somites; one or more of these may also form a segment; the cephalic segment may consist of several somites, and is conveniently called by Professor Huxley the peristomium, the terminal segments, the pygidium; but each somite, as a general rule, has a certain number of appendages: these, Professor Huxley calls parapodia-each parapodium divides into two portions, a notopodium and neuropodium. Now, it strikes us, if this nomenclature had been attended to, and enlarged as occasion required, our knowledge of the external anatomy of the Annelids would have been much more clear and exact. We call attention to this subject here, in the hope that future writers on this group of animals may be induced to abandon the old style and adopt the

new.

Following Grube, Dr. Johnston divides the Annelida into the Rapacia and Limivora, corresponding to the Errantia and Sedentaria of Milne-Edwards. As a Zoological convenience this division may be accepted for a short time longer; but there is no very sharp line of distinction to be drawn between the animals of either group. In the arrangement of the families and genera, Grube is not followed very explicitly. Taking Carus's arrangement of the families as a recent guide, we will see what genera and species are met with in this country. Of the Aphroditea, we have the genera Aphrodita (3 species), Lepidonotus (8 species), Polynöe (1 species), Pholöe (2 species), and Sigalion (1 species); of the Aphinomea, Euphrosyne (2 species), Spinther (1 species). There is no diagnosis of this latter genus given in the text, nor is the omission alluded to in the appendix. This is the more to be regretted as the original description in the Annals and Magazine of Natural History was, necessarily, very incomplete.

Of the Eunicea, we have Eunice (7 species), Onuphis (2 species). Dr. Johnston divides Audouin and Milne-Edwards' genus Onuphis

into two genera. Onuphis has pectinate branchiæ; the other, Northia, is distinguished by the absence of these organs. This latter genus, which was first published in this catalogue, is, we believe, badly defined, as one of the diagnostic marks of Onuphis is "branchia single or combshaped." We entertain serious doubts as to the correctness of the synonymic list. Of the two species of Onuphis (Northia), we may remark that the description of the first species, as given in the text, is by no means so elaborate as that given originally by Dr. Johnston, in the 16th volume of the Annals of Natural History; but on comparing both with the description given by O. F. Müller, we find many points of discrepancy. Unfortunately, the want of uniformity in the nomenclature prevents us from being positive on several points. Dr. Johnston's Onuphis, in his description given in the text, is convex on both dorsal and ventral surfaces. Müller's is " supra convexum subtus planiusculum;" Dr. Johnston says, "occipital segment, without any appendage." If this mean the peristomium, it is a mistake; if it refer to the second somite, counting the head, for the moment, as one, it does not hold good so far as the drawing is concerned, for in fig. 2 we see the second somite with appendages. In Müller's species the "collum" is "angustum et muticum," and the fig. tab. xviii. fig. 4 shows this. In Dr. Johnston's, the second somite (the neck) is broader than the head. In the specimen first described by Dr. Johnston the posterior somites were wanting, so that the character "anal segment with two styles," is simply borrowed from Müller, To the synonomy of the second species, O. conchilega, we may add, even after reading the foot note, the O. Eschrichtii of Oersted. Of Lysidia (not Lycidia) we have 2 species, of Lumbrineris 1.

Of the Nereida we have Nereis, with eight species, and we doubt not many more; of Nereilepas one species, of Heteronereis five. Of the Nephthyaceae, reduced to a subgenus of Nereida by Carus, we have Nepthys with three species. Of the Glycerea we have Glycera with six species; and Goniada with one. Of the Phyllodocca, Phyllodoce with seven species. Of the Hesionea, Psamathe, which Carus reduces to a synonym of Cirrosyllis of Schmarda. We think it will be found on examination that C. fusca of Johnston is not the C. punctata of Müller, unless indeed, as hinted by A. Agassiz, it turns out that the curious difference in the first fifteen somites is owing to the one being a parent stock' of the other. It is strange that this difference, though well figured on Plate xvi., is not alluded to in the text.