malogy,' should protest against the combination of the Greek prefix to the Latin noun, I can only plead that servility to a particular source of the fluctuating sounds of vocal language is a matter of taste; and that it seems no unreasonable privilege to use such elements as the servants of thought; and, in the interests of science, to combine them, even though they come from different countries, where the required duty is best and most expeditiously performed by such association.

Fig. 2.

For the same motive that suggested the term basi-occipital, viz. because the anthropotomist has been long accustomed to hear that and the corresponding element of the sphenoid bone described as 'basilar processes,' I propose to substitute the term 'basisphenoid' (basisphenoideum, Lat.) for the three different descriptive phrases applied to the part (5, figs. 2, 5, 19, &c.) by Cuvier, for the two additional synonyms of Geoffroy, and for the 'sphenoideum basilare' of Hallmann. 'Alisphenoid' (alisphenoideum, Lat., 6, 6, figs. 2.5, 19, &c.) seemed to retain most of the old anthropotomical term of alæ majores,' or wings 'par excellence' of the os sphenoideum; as 'orbitosphenoid' (orbito-sphenoideum, 10, 10, figs. 3 and 20) best recalls or expresses the idea conveyed by the descriptive phrase 'alæ orbitales,' or 'ailes orbitaires,' often applied to the homologous bones, regarded as processes of the sphenoid in human anatomy. Here, however, in reference to the alisphenoid, we find the first marked discrepancy in the conclusions of the anatomists who have particularly studied its special homologies. The bone which appears as the 'grande aile du sphénoïde' to Cuvier and Agassiz in fishes, is the petrosum to Hallmann and Wagner; it is also rocher' (petrosal) to Cuvier himself in reptiles, and is again grande aile du sphénoïde' in birds and mammals. The reasons which have led me to the conclusion that the bones so denominated, as well as the 'ptéreal' and 'prérupeal' of Geoffroy, are homologously one and the same, are so intimately linked with the consideration of the true petrosal and of other elements of the anthropotomist's 'temporal bone,' that I reserve the discussion of these questions until I have completed the apology for the names proposed in the first column of Table I.

Disarticulated mesencephalic or neuro-parietal arch, viewed from behind: Cod-fish.

The 'parietal' (parietale, Lat., 7.7, figs. 2, 5, 19, &c.) and 'mastoid' (mastoi deum, Lat., 8, 8, figs. 2, 5, 19, &c.) are amongst the few bones that have had the good fortune to receive, originally, definite names, applicable to them throughout the vertebrate series; although the mastoid, being like the paroccipital, essentially a parapophysis, loses its individuality sooner than do other bones of its segment, and becomes, therefore, a 'processus mastoideus ossis temporis,' in the language of anthropotomy. The homology of the 'parietal' has fortunately been, with a single exception, universally recognised throughout the vertebrate subkingdom; the exception being furnished by the eccentric homologist Geoffroy, who is, as usual, inconsistent with himself, even on this plainest and least mistakeable point.

Fig. 3.

The term 'presphenoid' (presphenoideum, Lat.9, figs. 3, 5, 20, 24, 25,&c.) is proposed for the sphénoïde antérieur,' on the principle of substituting, as the better instrument of thought, a definite name for a descriptive phrase. For the same reason 'postfrontal' (postfrontale, Lat., 12, 12, figs. 3, 5, 20, &c.) is substituted for Cuvier's 'frontal postérieur' and its synonyms. The 'frontal' (frontale, Lat. 11, figs. 3, 5, 20, &c.) and vomer' (vomer, Lat., 13, figs. 4, 5, 20, 25), are among the few bones which have had their special homologies recognised unanimously throughout the vertebrate subkingdom; in the one case even without departure from the original anthropotomical name, and in the other, with but a single deviation from the established nomenclature. But when Geoffroy was induced to reject the term 'vomer' as being applicable only to the peculiar form of the bone in a small proportion of the vertebrata, he appears not to have considered that the old term, in its wider application, would be used with

out reference to its primary Disarticulated prosencephalic or neuro-frontal arch, viewed from behind: Cod-fish. allusion to the ploughshare, and

Fig. 4.

that becoming, as it has, a purely arbitrary term, it is superior and preferable to any partially descriptive one. Rhinosphénal,' it is true, recalls the idea of the vomer forming the continuation in the nasal segment of the skull of the basi- and pre-sphenoidal series of bones in other segments; but 'vomer,' used arbitrarily, summons equally every idea derived to form the complex whole from the general study of the bone throughout the vertebrate series. "Prefrontal' (prefrontale, Lat., 14, 14, figs. 4, 5, 21, &c.) claims the same preference over anterior frontal, and its foreign equivalents, as does postfrontal over its synonymous phrases. There is also another reason for proposing the term; viz. because it is applied to bones in the vertebrate series generally, according to conclusions as to their homological relations, which differ from those to which Cuvier and Geoffroy had arrived. The discussion of the discordant denominations at present applied to this important element of the skull will be fully

carried out in the sequel. Nasal' Disarticulated rhinencephalic, or neuro-nasal arch, (nasale, 15, figs. 4, 5, 21, &c.) is another

of the few instances in which it is possible to retain and generally apply an old and received anthropotomical term. No one, it is presumed, will con

tend for the perpetual expression or insertion of the understood generic word 'bone' or 'os' in this case any more than in the parietal, frontal, &c., which, from being originally specific adjectives, have been properly and conveniently converted into definite nouns.

6

In conformity with this mode of acquiring an improved as well as brief and precise expression of anatomical facts, I have substituted for 'pars petrosa' or 'os petrosum' the substantive term 'petrosal' (Lat. petrosum, figs. 5, 25, 16). The necessity for some such designation for an essentially and often physically distinct bone in the vertebrate skull has been felt by both Cuvier and Geoffroy, when they respectively proposed the names 'rocher' and 'rupéal' for the element in question. Petrosal' has appeared to me to be the best English equivalent of Cuvier's rocher'; as containing the most characteristic vocable of the old anthropotomical descriptive phrase 'pars petrosa ossis temporis,' &c. 'Rupéal' unfortunately has no determinate meaning: it is applied by its author with certain prefixes to several distinct bones, which already had their proper names. 'Sclerotal' (sclerotale, Lat., figs. 5, 22, 23,17) for ossicula seu laminæ osseæ membranæ scleroticæ,' is proposed on the same grounds as exoccipital, post frontal, &c., viz. the substitution of a name for a phrase. The sclerotals have not been usually included amongst the bones of the head, though they have precisely the same claims to that rank as the petrosals, or other bony capsules of the organs of special sense. Retaining the old anthropotomical term 'ethmoid,' I restrict its application to the very irregular and inconstant developments of bone in the cartilage or membrane which is applied to the anterior outlet of the cranium proper, for the support or defence of the cranial part of the organ of smell. The 'ossa turbinata superiora,' and the 'cellulæ æthmoideæ' are parts of the capsule of that sense, extensively developed in the mammalia, to which the term ethmoid may properly apply; but they must always be distinguished from the modified though constant neurapophyses of the nasal vertebra, called 'prefrontals,' with which the above developments of the olfactory capsule usually coalesce in birds and mammals. "Turbinal' (turbinale, Lat., figs. 5, 25, 19), like petrosal, is a substitute for the phrase 'os turbinatum inferius,' and its synonym 'os spongiosum inferius.'

'Palatine' (palatinum, Lat., ib. 20) is another of the few fortunate instances of the general recognition of the homologous bone throughout the vertebrate kingdom, with the further advantage of a steady retention of a good old name.

Maxillary' (maxilla, Lat., ib. 21) is a similar instance; but Geoffroy, as usual, makes himself singular by adding an uncalled-for synonym. If Soemmerring's term 'mandibula' for the lower jaw were universally adopted and constantly understood to signify the totality of that part of the tympanomandibular arch throughout the vertebrate series, it would be unnecessary to encumber' maxilla' with the distinctive epithet 'superior,' which, indeed, expresses a character peculiar only to Man and a few mammalia: in the vertebrate series the 'maxilla' is more commonly anterior than superior to the 'mandibula.'

I have adopted the term 'premaxillary' (premaxillare, Lat. ib. 22), as used by M. de Blainville and some other distinguished continental osteologists, in preference to 'intermaxillary;' because that term has already been applied (by Schneider) to another bone of the skull (the tympanic in birds), of which it is more accurately descriptive, than it is of a bone which is more commonly before than between the maxillary bones. Entopterygoid' (entopterygoideum, Lat.) claims preference to the phrases 'ptérygoïde interne' of Cuvier and Agassiz, on the same logical grounds as have already been urged in favour of exoccipital,' ' prefrontal,' &c. But I have also another reason for proposing a definite term for the bone 23, fig. 5, which I regard as a peculiarly

ichthyic development. Cuvier has applied the term 'ptérygoïde interne' to another part of the diverging appendage of the palato-maxillary arch, which part, I concur with Dr. Köstlin in regarding as homologically distinct from the entopterygoid' of fishes. For the part in question, viz. the 'os transverse' of Cuvier in the skull of fishes (24, fig. 5), and its homologue in reptiles, which he calls 'ptérygoïdien interne' (24, fig. 22), I retain the term 'pterygoid' (pterygoideum, Lat.), meaning pterygoid proper: and to the bone which Cuvier calls transverse' in reptiles (24', fig. 22), I apply the term 'ectopterygoid' (ectopterygoideum, Lat.); but this, as the table demonstrates, does not signify Cuvier's os transverse' in the skull of fishes. Entopterygoid, pterygoid and ectopterygoid, have, therefore, both the advantages of substantive terms, and of being applied steadily each to a distinct bony element. The 'hérisséal' of Geoffroy, like the 'ptérygoïde interne' of Cuvier, means one thing in a fish and another in a crocodile; Geoffroy has also encumbered the latter bone with a third synonym. Malar' (malare or os malæ, Lat.) is preferable to 'jugal,' because Cuvier applies that name to one bone in a fish, to another in a mammal, and to two essentially distinct though coalesced bones in a bird. Malar is also the name most commonly applied by English anthropotomists to the bone, to the true homologue of which I would restrict its application throughout the vertebrate series.

་

With regard to the 'squamosal' (squamosum, Lat. pars squamosa, &c., figs. 22-25, 27), it may be asked why the term temporal' might not have been retained for this bone. I reply, because that term has long been, and is now universally, understood in human anatomy to signify a peculiarly anthropotomical coalesced congeries of bones which includes the 'squamosal' together with the 'petrosal,' the 'tympanic,' the 'mastoid,' and the 'stylohyal.' It seems preferable, therefore, to restrict the signification of the term temporal' to the whole (in Man) of which the squamosal' is a part. To this part Cuvier has unfortunately applied the term 'temporal' in one class and 'jugal' in another: and he has also transferred the term 'temporal' to a third equally distinct bone in fishes; whilst to increase the confusion, M. Agassiz has shifted the name to a fourth different bone in the skull of fishes. Whatever, therefore, may be the value assigned to the arguments which will be presently set forth, as to the special homologies of the 'pars squamosa ossis temporis,' I have felt compelled to express the conclusion by a definite term, and, in the present instance, have selected that which recalls best the accepted anthropotomical designation of the part, although 'squamosal' must be understood and applied in an arbitrary sense, and not as descriptive of a scale-like form, which, in reference to the bone so called, is rather its exceptional than normal figure in the vertebrate series. The term 'tympanic' (tympanicum, Lat.) appears to have received the most general acceptance as applied to that bone which the early ornithotomists have called 'os quadratum' and 'os intermaxillare,' (fig. 23, 28) and which as a process of the human temporal, sometimes called 'external auditory,' supports the tympanic membrane (fig. 25, 28). 'Caisse' is the French and 'pauke' the German equivalent; but Cuvier more commonly uses the phrase 'os tympanique.' The chief point, in reference to that term, as applied by Cuvier, from which I find myself compelled to dissent from the great and ever-to-be-revered anatomist, relates to the view which he has taken of the large and long pedicle which supports the mandible in fishes, and which, in that class, is subdivided into sometimes two, sometimes three, and commonly into four pieces. I regard this subdivision of the elongated supporting pedicle as explicable chiefly, if not solely, by reference to a final purpose, viz. to combine strength with a certain elastic yielding and power of recovery, in the constant and powerful movements to which it is subject in the transmission of the respi

ratory currents, and in the prehension and deglutition of the food. Cuvier himself regards in the same light the analogous subdivision of the mandibular or lower half of the arch, and both Conybeare* and Buckland † have well illustrated the final purpose which the subdivision of the lower jaw of the Crocodile into overlapping pieces, subserves. Cuvier has given distinct and convenient names to these several pieces of the mandible, but he views them collectively as answering to the simple mandible of the mammal and the bird. 1, in like manner, regard the subdivided pedicle supporting the mandible in fishes as answering to the undivided pedicle supporting the mandible in ophidians, lizards and birds. There is the same necessity or convenience for a distinct name to each distinct part of the tympanic pedicle, or upper part of the tympano-mandibular arch, as for the divisions of the mandible or lower part of that arch. But Cuvier unfortunately persuaded himself that the subdivisions of the tympanic pedicle in fishes represented other bones in higher vertebrates besides the tympanic, and applied to them the names of such bones. I have been compelled, therefore, in dissenting from this view to propose new names for the peculiar ichthyic subdivisions of the tympanic, and in doing so I have been careful to retain the dominant term, and to distinguish the parts by prefixes indicative of their relative position. Time and the judgement of succeeding homologists will determine the accuracy or otherwise of this view; and, should it be ultimately adopted, I feel great confidence that the terms 'epitympanic' (epitympanicum, Lat., fig. 5, 28a), mesotympanic (mesotympanicum, 28b), pretympanic (pretympanicum, 28c) and hypotympanic (hypotympanicum, 28d), will be preferred to the names proposed by Geoffroy St. Hilaire for the same parts. With regard to the subdivisions of the mandible in cold-blooded vertebrates, I adopt most of those proposed by Cuvier. As, however, 'operculaire' had been applied by the great anatomist to a distinct bone in fishes, it was necessary, in order to avoid its use in a double sense, to substitute a distinct name for the part of the jaw in question, and as it is always applied, like a surgeon's splint or plaster to the inner side of most of the other pieces, that of 'splenial' (splenium, Lat., figs. 22, 23, 31) suggested itself to me as the most appropriate name. For an obvious reason I have restored the term 'coronoid' (coronoideum, 31') in place of 'complementary,' for the piece into which the crotaphite muscle is always more or less inserted in the mandible of reptiles. There is no ground for disturbing the appropriate names given by Cuvier to the parts of the diverging appendage of the tympano-mandibular arch in fishes; and the same principle which he has adopted in distinguishing the different opercular bones (fig. 5, 34-37), has guided me in naming the different parts of the bony pedicle which supports them.

I have gladly adopted as many of the well-devised terms which Geoffroy proposed for the elements of the hyoid arch, as his unsteadiness in their application would permit to be retained. They are obviously preferable to the descriptive phrases by which Cuvier designates the homologous parts.

The substantive terms applied to the corresponding divisions of the branchial arches have been modelled on those of the hyoid system; but I have deviated in one instance from the rule which has governed throughout my nomenclature of the bones, in proposing a second name for a modified homologue in the air-breathing animals, of a part of the branchial apparatus in fishes, viz. that part which is retained even in the human hyoid, and which is known in anthropotomy as the 'os laterale linguale,' or 'cornu majus ossis hyoidei;' for this part I have proposed the name 'thyrohyal,' for the reasons assigned in the note (2) to Table I.

The names assigned to the bones of the scapular arch (figs. 5, 22, 23, 24, 25, * Geol. Trans., vol. v. p. 565. + Bridgewater Treatise, vol. i. p. 176.