rales magni. Corpus sacciforme, collo coarctato, tubo conico exserto, apice aperto. A. Corpus testaceum. a. Testa unilocularis. b. Testa laminis transversis multilocularis. B. Corpus nudum=Sepia, Lin. * In Britain Conchology was thoroughly Linnæan; and the very names of Cuvier and Lamarck were scarcely known to its followers when, in 1815, the peace opened up access to the continent. That there were students in the art amongst us, to some numbers, is made certain by the publication of several Introductions, and by the active diligence displayed in the search more especially of indigenous shells. Lister laid the foundation of a native conchology on which no other could then build; but, to its ultimate completion, Petiver contributed a few species, Pennant something more, and Da Costa also something in a separate volume, published in 1778, of considerable pretensions and some merit.† They found successors in men of like minds and capacity, amongst whom it is sufficient here to specify Mr. Boys, of Sandwich, the first to investigate our minute shells, Dr. Pulteney, Mr. Donovan, Mr. Adams of Pembroke, and Captain Laskey, who carried these researches into Scotland, researches which were cloaked with the veil of science to hide their real nature, for I do not overstate the truth when I tell you that they were in reality instituted more to gratify an innate taste for collecting things beautiful and rare, than for any wider object. In 1803, Mr. Montagu, however, enriched us with his "Testacea Britannica," which was completed in 1808. In the preface some misgivings of the perfectness of the Linnæan system are feebly hinted; and, in the body of the work, a very few additional genera are defined, with an apology for the bold innovations; but, albeit willing enough to look in this direction, we cannot see in these symptoms the small cloud that was about to usher in the fruitful change. For shortly before the completion of the "Testacea Britannica," there appeared, in the Linnæan Transactions, a descriptive catalogue of the British Testacea by Dr. Maton and the Rev. Thomas Racket,+-men of note in their day, and the work was well done in the established fashion, slavishly Linnæan in manner at least, with its definitions and divisions, its trivial and natural characters, a Historia Animalium Angliæ tres tractatus. Lond. 1678. Historia naturalis Testaccorum Britanniæ; or, The British Conchology, &c. By Emanuel Mendes da Costa. 4to. Lond., 1778. Vol. viii. Lond., 1807. goodly display of synonymes, and not one word of animal structure, or of the economy of the creatures that builded the models they described. When we were students this catalogue of Maton and Racket's was in high estimation, and we have heard it dictatorially pronounced to be an excellent model, in a sort of pseudo-critical comparison of it with Montagu's ever-during work! This very slight sketch gives you a true picture of what Conchology was with us in 1815 and for some subsequent years; but a change was at hand, which was effected by the joint labours of Dr. Leach, the Rev. John Fleming, and Mr. John E. Gray.* Dr. Leach cast aside contemptuously the fetters of the Linnæan school, and, with ardent vigour, he adopted and advocated the French systems, which he sought to improve by working in the same direction, and under the guidance of the same principles. He, however, published little that bore directly on Conchology. He was the first to propose the division of the naked Cephalopods into two families, from the number of their tentacular feet; he first discovered the true structure of the ligament of the Bivalves; and he, discriminating their peculiar features, collected certain species under new genera or families, for he was very nice in detecting differences amid common resemblances, and attached too much importance to slight variations from his fondness for analysis. On the contrary, his friend Dr. Fleming, a Scotch clergyman, proceeded with the caution which is said to be characteristic of his countrymen. In his interesting article, "Conchology," contributed to the "Edinburgh Encyclopædia," and published in 1815, he has stated many obvious objections to the system of Linnæus; and he has given outlines of those of Bruguiere, Bosc, and Lamarck, which he ventured rather faintly, however, to praise. As he limited himself, in this article, to the description of British shells, he did not indicate his views of the arrangement of the Mollusca in general; and the subjoined outline of his partial method will show you how purely conchological and Linnæan this eminent and sagacious naturalist was at this period: * In 1822 the Elements of Conchology, including the Fossil Genera and the Animals, by T. Edward Bowdich, was published at Paris,-a very useful work, but little known in this country, and hence its influence must have been inconsiderable. Yet it would seem that in 1825 Lamarck's system began to have some favour, for an epitome of it was published by Charles Dubois, F.L.S., in that year. The low estate of conchology amongst us is, however, made more evident by this work, for in his translation, Mr. Dubois omits all the characters derived from the animals. Order I. UNIVALVES. Division I. UNILOCULAR. SECTION I. ASTULIDIA. Shells destitute of a pillar or columella upon which they are formed. The "Univalvia absque spira regulari" of Linnæus. Family 1. EXPANDED. Genera: Patella, Haliotis, 2. TUBULAR. Genera: Dentalium, Cæcum, Serpula. Family 3. FLASK-SHAPED. Genus: Lagena. 4. SPIRAL. Genera: Spirorbis, Planorbis. SECTION II. STULIDIA. Shells more or less spiral and revolve round a central pillar or columella. The "Univalvia spira regulari" of Linnæus. Family 1. TURRETED. Tribe 1. Canaliculated. Genera: Buccinum, Murex, Strombus. 2. Entire. Genera Turbo, Odostomia, Lymnæa. 2. GLOBOSE. Genera: Helix, Nerita, Trochus. 3. CONVOLUTED. Genera: Cypræa, Voluta, Bulla. Division II. MULTILOCULAR. Genera: Nautilus, Orthocera, Spirolina, Miliola. Order II. BIVALVES. Division I. DENTATED. Genera: Mya, Ligula, Solen, Tellina, Pandora, Corbula, Cardium, Cyclas, Mactra, Lutraria, Donax, Venus, Isocardia, Terebratula, Nucula, Arca, Pectunculus. Division II. TOOTHLESS. SECTION I. INEQUIVALVE. Genera: Pecten, Ostrea, Anomia. SECTION II. EQUIVALVE. Genera: Mytilus, Pinna. Order III. MULTIVALVES. Division I. DENTATED. Genera: Pholas, Teredo. Division II. TOOTHLESS. SECTION I. OPERCULATED. Genera: Balanus, Coronula. But in 1820, when Dr. Fleming published the article "Mollusca" in the same Encylopædia, he had shaken off the Linnæan yoke, and had become a follower of Cuvier, without treading exactly in his steps, as if resolute not to wear the livery of his master, while, at the same time, he derived from him his sustenance and position. What led Dr. Fleming truant and aside, as I deem his deviations from Cuvier to have been, was the importance he attached to the binary method of analysing the great classes of animals into their less and lesser divisions,--a method which may often be called into useful aid when the search after a genus by artificial devices is alone the object, but which adhered to in any system that pretends to arrange animals according to their affinities, as indicated by their general identity of structure, and that was Cuvier's object,-will sever far asunder kindred races.* The truth of this remark is made obvious by an examination of Dr. Fleming's method, which we extract, as re-printed in his very valuable work, the "Philosophy of Zoology," ann. 1822. Dr. Fleming, in the preface to his " Philosophy of Zoology," has vindicated his predilection for this binary method, in some remarks which are worth quoting. "There is now much declamation about the worthlessness of Artificial Systems, and the excellence of Natural Methods. But this excellence is more apparent than real. Many of those natural groups which are so much praised are ill defined, and it is even acknowledged by their admirers that precise limits cannot be assigned to them. Hence it frequently happens that the definition of the group is applicable to a few genera only, which are considered as its type, and does not embrace other genera which are regarded as belonging to it, but beginning to assume the characters of some of the other neighbouring groups. There is here the use of a method where there is no precision, and a boasting that the plan of nature is followed, when that plan is confessedly incomprehensible. Indeed, it often happens that the admired natural method of one zoologist differs from the censured artificial method of another, merely in the circumstance that different systems of organs have been made choice of as the basis of the respective classifications. Unless zoologists, in the formation of their primary groups, endeavour to determine those characters which all the members possess in common, admitting only such marks into the definition, and practise the same method with all the subordinate divisions, the progress of the science will be unsteady, the student will be startled at its contradictions, and the revolutions in nomenclature become as frequent as the cultivators of the science are numerous.' Order I. INVERTEBRATA.--GANGLIATA. MOLLUSCA. DIVISION I. MOLLUSCA CEPHALA. Class I. CEPHALOPODA. Order II. Sepiada. (1.) Head surrounded with eight arms and two feet. Sepia, Loligo. (2.) Head surrounded with eight arms, without feet. Octopus, Eledona, Ocythoe. Class II. PTEROPODA. I. With a shell. Limacina, Hyalea. II. Destitute of a shell. A. Fins double. Pneu modermon, Clio, Cleodora. B. Fin single. Cymbulia. Section II. GASTEROPODA. Class I. PULMONIFERA. Order I. Terrestrial. Subdivision I. Cloak and foot parallel. Arion, Limax, Parmacella, Testacella, Veronicellus, Onchidium. Subdivision II. Cloak and foot not parallel. Tribe I. Foot with a lid. Cyclostoma. Tribe II. Foot destitute of a lid. Helix, Bulimus, Pupada, Vitrina, Succinea, Achatina. Order II. Aquatic. Subdivision I. Body protected by a shell. Tribe I. Shell spirally twisted. A. Shells turreted. Lymneus, Physa, Aplexa. B. Shells depressed. Planorbis, Segmentina. Tribe II. Shell conical. Ancylus. Subdivision II. Body destitute of the protection of a shell. Peronia. Class II. BRANCHIFERA. Order I. Branchiæ external. Tribe I. Branchiæ exposed. A. Branchiæ issuing from the cloak dorsally. |