confidence of success and the supposed magnitude of their discoveries. I have received a curious newspaper, "The Future," published at Richland, Shawnee Co., Kansas, U.S., which promises magnificently and gives much advice to agriculturists.

I was a boy when London was thrown into a spasm of temporary insanity by "Murphy's Weather Almanac." It was all done by one lucky hit. Anybody may make an almanac and predict the weather for each day in the year, and be right more frequently than wrong, by simply taking the averages from meteorological observations and predicting accordingly; but Murphy was bolder than this. He pre. dicted that a certain day early in the year would be phenomenally cold, and it was so ; 28 degrees below freezing in Hyde Park. Then followed a rush to buy the almanac, and a ridiculous excitement. Songs were sung in the streets, and wild stories were told of the magnetical and electrical discoveries of the great meteorological Murphy.

In spite of all our meteorological observatories and observations, we are still unable to make any far forward predictions of weather beyond stating probable averages. Storm warnings are fairly reliable, but these and the rest of the daily forecasts of the Meteorological Office are not exactly predictions. They are statements of atmospheric movements that are proceeding in certain directions, and which, if they continue, will reach certain localities a few hours later. They do commonly continue as anticipated, but not certainly. About eighty per cent. of the forecasts are fulfilled, and the rest are failures.

A really valuable contribution to weather-wisdom was read at the last meeting of the British Association by Dr. Courteney Fox, "On Some of the Laws which Regulate the Sequence of Mean Temperature and Rainfall in the Climate of London." These laws are induced from observations extending over the last seventy years. They are necessarily empirical, i.e., all mere generalisations of average fact, not deductions from necessary causation. Dr. Fox finds that if a spring or a summer be very cold, the succeeding season will be cold, and that warm autumns succeed very warm summers. It is very rarely that a dry August is followed by a wet September. A very wet and cold summer is usually succeeded by a cold autumn. If January, April, June, July, August, September or December are very cold, the succeeding month will probably be dry. Very warm January, expect a dry February. The next month following a very warm June, July, or August will be warm. Very wet January, March, or April, usually followed by a warm month. Warm and wet November and December, wet month to follow. Warm and wet January, expect a warm February. A warm month usually follows a warm and dry June or July, and a wet September follows a warm and dry August. Cold and wet July and August, expect cold month to follow. Cold and dry December, expect cold

A difficulty is suggested on reading these indications, viz., that of finding when the changes come. In nearly all the cases specified the order for the next month or next season is, "As you were." I suppose that we must read all these descriptions of the preceding period as intended for exceptional weather, and that such weather usually shades off gradually, while the more decided changes more commonly follow average weather.

I am glad to find among the papers read in Section B (Chemistry), one by Professor Odling, which has the merciful intent of relieving us from some of the structural names which are daily poured upon the unhappy student of organic chemistry. Every plant that has an odour, or has a flavour, or contains any thing that has any special property, may be tortured until it yields some substance with real or imaginary special composition and properties, and every such substance may be physicked with strong acids or strong bases, or chlorine, iodine, bromine, &c. &c., and forced into some sort of combination with these ; and the compounds thus formed may unite with other compounds, and thus on, ad infinitum. Millions of millions of such things may be concocted, then analysed, then formulated, and then named according to their imaginary molecular constitution. Now that we have hundreds of young aspirants for chemical fame who devote themselves to such mixing, and messing, and analysing, and naming, the torrents of papers poured into the learned societies combine to produce a flood that is simply maddening, and would drive all our chemists into lunatic asylums, but for a protecting providence which has ordained a beneficent law that operates with stern rigidity; viz., that nobody but the author and the printer ever reads these papers. I pick up at random the two last numbers (October and November) of the "Journal of the Chemical Society," and find among the abstracts of papers on Organic Chemistry more than a hundred of these new substances discovered during each current month. This has been going on for years, and may go on for ever, if the supply of ordinary laboratory aspirants is maintained. As an example of the sort of names which Professor Odling desires to reform, I will quote two or three from one of the numbers of the journal above named. "Orthochlorocarbonylphenylorthophosphoricdichloride," obtained by R. Anschütz, and re-named as above, its original name given to it by Couper, trichlorophosphate of salicyle, being too short (page 1062). Tetrachloroquinonemetanitraniline," obtained in black crystals by M. Niemeyer, together with a dozen of other chemical cousins (page 1066). E. Bamberger and S. C. Hooker present us with several of their new-born chemical babies, among which is one that bears the pretty name of "hydroxyisopropyldiphenyleneketonecarboxylic acid," which is described as "a strong

66

acid containing only one carboxyl group " (page 1070). When its younger brothers, containing several carboxyl groups are born, and named according to their more complex composition, the result may be imagined. These are all culled from pages 1062 to 1070 of the October number. I have marked others in the November number, but in mercy to my readers will not quote them.

Professor Odling proposes to supply empirical names instead of these, justly observing that "the primary purpose of a name is undoubtedly to designate and not to describe." In "The Gentleman's Magazine" of October, 1880, I illustrated the result of this principle of naming a thing by a description of its composition, by applying it to the case of our familiar Christmas-pudding, Suetofloureggcandied peelraisinspicecurrantsconglomerate, would thus be its pretty little title.

As the primary object of 99'9 per cent. of the researches which produce these violent neological outbreaks is to establish the reputation of the analyst, why not carry out this purpose more effectually by bestowing upon these new concoctions the names of their parents, with a distinctive prefix? Thus Smith's chemical first-born might be named Alpha Smith, his second Beta Smith; then Gamma, Delta, and on to Omega Smith. After this Alpha A. Smith, Alpha B. Smith, &c., to the end of the Roman alphabet. This would supply 24 × 26 = 624 names, after which numerals might be used, 625 Smith, and so on to the required number of thousands.

six-sided teeth are arranged in seven rows (fig. 181), the median row consisting of much elongated plates, and the three lateral rows on each side, of small hexagonal plates. About eleven species are recorded* from the London Clay, and the Bracklesham and Barton beds, the most important being M. Toliapicus and M. Dixoni, and associated with them are examples of caudal spines. The dentition of Etobatis, also found in the same strata, differs from that of Myliobatis in consisting only of a single row of plates (fig. 182). About six species of this genus have been described from the English Eocenes, but the fact that the teeth

Fig. 181.-Teeth of Myliobatis.

Fig. 182.-Straight teeth of Etobatis.

CHAPTERS ON FOSSIL SHARKS AND RAYS.

By ARTHUR SMITH WOODWARD.

V.

MYLIOBATIDEÆ.

OME of the largest and most pelagic of the living

remains of at least three genera are not uncommon in the Tertiary deposits, both of this country and the Continent. One of their most characteristic features, and that which is of greatest interest and importance to the palæontologist, consists in the nature of the Identition. The mouth is armed with a number of flat crushing plates, often united firmly together by sutures and varying in arrangement in the different genera; they are placed in successive transverse series, and as the front rows become unfit for use, they fall out of the mouth, being replaced by new ones from behind. These dental plates, together with specimens of the barbed spine fixed upon the tail of some forms, constitute all the known fossil evidence, and are met with in Eocene strata at Sheppey, Bracklesham, and Barton; in Miocene at various Continental localities;, and in the Pliocene Crag of Norwich. The type-genus is Myliobatis, in which the

Fig. 183.-Arched teeth of Etobatis.

of one jaw are sometimes nearly straight (fig. 182), while those of the other are considerably arched (fig. 183), renders the specific determination of detached plates somewhat uncertain. Zygobatis (fig. 184) is another form, referred to the living Rhinoptera by Dr. Günther, and characterised by the disposition of the dental armature in seven longitudinal rows, as in Myliobatis; here, again, the plates are six-sided, and also united to form a tessellated pavement, but besides the relatively great breadth of the middle series, the two adjacent rows are also considerably elongated in a lateral direction, and there are thus only two

Dixon's "Geol. and Foss. Sussex," 1st edit., pp. 197-200 see also "Agassiz' "Rech. Poissons Fossiles."

and as it is the custom to restrict the term to those spines whose precise relationships are indeterminable, in consequence of their never having been found in association with definite fragments of the rest of the fish-structures, to which they originally belonged, the number of forms included in this category has been considerably reduced by the progress of research. Among those removed, for example, are the Devonian Parexus (of which an outline is given in fig. 185), the Carboniferous Ctenacanthus and Pleuracanthus, alluded to in previous articles, the Jurassic Leptacanthus, now known to belong to a Chimæroid (Ischyodus) and many others. But there are still a large number that can be referred to no very definite place, and though they may not all be truly Selachian-as is quite probable, and has proved to be the case with Parexus and Leptacanthus just mentioned-it will be convenient to group the whole together until our information becomes more complete. Some forms appear to have been placed in front of dorsal fins (as shown in the drawing of Spinax, Vol. XX. p. 172, or in fig. 185, a); others were almost certainly pectoral or ventral fin-spines and perhaps situated like those of the curious Acanthodian fishes (fig. 185, b); and others, again, may correspond to the little triangular dermal scutes (fig. 185, c) that are also to be found in pairs in the same primitive tribe. Nearly all are ornamented on the external surface with variously disposed ridges and tubercles, often enamelled, and the portion embedded in the tissues of the body-the extent of which varies considerably in the different forms-is usually smooth or finely striated. Moreover, all agree in being destitute of any articular facettes at the lower end, thus indicating the cartilaginous state of the skeleton with which they were once connected; and the presence of an internal cavity, opening lengthwise behind and below, or simply in a hole at the base, is also evidently a constant character.

The earliest of these dermal weapons hitherto described is the little Onchus (fig. 186) from rocks of Upper Silurian age. With the exception of Scaphaspis ludensis, from the Lower Ludlow of Leintwardine (Shropshire), and the doubtfully piscine conodonts, it is the oldest evidence of the existence of vertebrate life yet known. In Britain, it occurs in the celebrated Ludlow bone-bed, and in the passage beds between the Silurian and Old Red Sandstone strata of the same area, and quite lately, spines of a similar type have been recorded* as occurring in beds of a slightly earlier date in America; but the remains originally ascribed to this genus from strata of the carboniferous period appear, from more recent discoveries, to belong rather to such forms as Physonemus and Ctenacanthus. The external surface is characterised by thick and smooth longitudinal ridges, and the

most distinctive feature of the spine is the absence of posterior denticles.

The Old Red Sandstone and Devonian-at least in this country-yield no ichthyodorulites of importance, but almost all divisions of the Carboniferous are replete with examples of the greatest interest. The largest forms hitherto discovered are met with in the Carboniferous Limestone, Phoderacanthus grandis,* from Bristol, probably attaining a length of no less than three feet. Among others, we may especially refer to those known under the names of Gyracanthus, Orthacanthus, Acondylacanthus, Lepracanthus, and Erismacanthus.

Gyracanthus is a genus first established by Agassiz, and more completely elucidated since by the researches of Hancock, Atthey, and Traquair, upon a much larger series of specimens: it ranges throughout the whole of the Carboniferous strata, though not yet known to extend either above or below, and is socalled in allusion to the peculiar appearance of the spine produced by the arrangement of the ornamentation (fig. 187). The ichthyodorulite is characterised by its very slightly compressed form,-almost round in transverse section,-by an extensive internal cavity, and a long base of insertion; some examples are of considerable size, attaining a length of sixteen or eighteen inches, and almost all that are referable to adult fishes exhibit a long worn surface at the tip (fig. 187, a), evidently due to constant friction with the bed or sides of the water in which their original possessors lived. It is further noticeable that—instead of being symmetrical-all these spines are distinctly "lefts" and "rights,"—a fact suggesting that they occurred in pairs, and taken in conjunction with the wearing of the tips, doubtless indicating that they were placed in front of pectoral or ventral fins. Messrs. Hancock and Attheyt believed, also, that they had discovered a few symmetrical spines of the same type, and hence regarded the latter as dorsal; but Dr. Traquair‡ has more recently shown that there is no unquestionable basis for such a conclusion, and considers it to have been founded upon imperfect materials. Associated with the ichthyodorulites, there often occur patches of small dermal tubercles, and occasionally also curious triangular bodies, once looked upon as the carpal cartilages of Gyracanthus. These are hollow and open at the base, with a roughened surface destitute of any ornamentation, and, from a study of their microscopical structure, Dr. Traquair has determined that they are truly dermal appendages. The number of species already described from British rocks is about seven, and the best known appear to be the G. tuberculatus and G. formosus, of which the coal

J. W. Davis, Trans. Roy. Dublin Soc., Ser. 2. Vol. I. (1883), p. 534, pl. lxv. Since description, the original specimen of this fine ichthyodorulite has been presented by Earl Ducie to the British Museum, where it is now to be seen. † Ann. and Mag. Nat. Hist., [4] I., 1868, p. 368. Loc. cit., [5] XIII., 1884, pp. 37-48.

measures of Northumberland have yielded a most extensive and instructive series, now in the Newcastle Museum.

The spines included under the name of Oracanthus (Agassiz) are of a very curious and problematical nature; they are more or less triangular in shape (fig. 188), sometimes twelve or fourteen inches in length, and ornamented externally with transverse rows of blunt tubercles or irregular ridges, but exhibiting no broad smooth surface for insertion in the soft tissues of the body. All possess a large internal cavity, opening at the base, and seem to have been originally arranged in pairs, for (like Gyracanthus) they are invariably "lefts" and "rights," and some show traces of terminal abrasion. O. Milleri (fig. 188) is the species to which the majority of the British fossils are referred, and with it Mr. J. W. Davis has recently* associated a number of dermal plates of various forms, on account of the close resemblance of their ornamentation; if the latter are correctly so placed, Oracanthus must have possessed a strong covering of armour-at least, in the region of the head, but any satisfactory evidence as to the facts is at present wanting. The genus appears to be exclusively confined to the Lower Carboniferous, the most abundant remains being those of O. Milleri just mentioned, from the Carboniferous Limestone of Bristol and Armagh, while others named O. pustulosus are sometimes met with in the equivalent beds of Oreton, Shropshire. (To be continued.)

ASTRONOMY AND METEOROLOGY FOR THE MONTH.

By JOHN BROWNING, F.R.A.S. VENUS will be an evening star throughout the

VENUS

month in Capricornus. She rises about eleven in the morning, souths about three in the afternoon, and sets at times varying between 7.12 and 8.3. Mercury will be an evening star until the 20th, and a morning star after that date, rising at times varying between 9.42 A.M. on the 3rd, and 6.21 on the 31st, and setting at 5 P.M. on the 3rd and 2.49 on the 31st. Mars will be in Leo, and will be in conjunction with the moon on the 27th at 9 o'clock in the morning, rising at 10.50 P.M. on the 17th, southing at 5.33 A.M., and setting at o hr. 13 mins.

Jupiter will be in Virgo, and will be in conjunction with the moon on the 28th at 9 o'clock in the norning. He will rise on the 3rd at 1 hr. 18 min. morning, south at 7 hr. 22 min. in the morning, and set at 1 hr. 26 min. in the afternoon.

Saturn will be almost stationary in Gemini, and will be in opposition on Dec. 26th at 10 in the

* Trans. Roy. Dublin Soc. [2], I. pp. 525-531, pls. lxii-lxv.

It is a highly interesting question how quickly the new star in Andromeda appeared, that is whether it was first visible to any observer faintly and then became brighter and brighter until it attained its fullest magnitude, which was probably about the 7th or 8th of October. For my own part I should think it must have almost flashed into existence at once, because the great nebulæ are constantly watched by so many observers that I do not think it could have been present for more than two or three evening. without being seen. Mr. Benjamin Kidd, of Bramley, Surrey, appears to have seen it at least two days before any other observer, as he noticed it on the Ist of September, though he did not write to Greenwich Observatory until the 3rd of September, because he waited to see it again.

Mr. Frank McClean, of Rusthall House, Tunbridge Wells, informs me that, seen with his 10-inch achromatic, the star on the 10th of November was scarcely brighter than many of the surrounding small stars, that is, it had waned probably to about the 12th or 13th magnitude.

I shall be glad of any further information on this subject.

In No. 2690 of "Astronomische Nachrichten," the attention of observers is called to the SearchingEphemeris for the periodic comet of Olbers of 1815, contained in Nos. 2613 and 2614 of that periodical. Its perihelion passage is calculated to occur on the 17th of December, 1886, with an uncertainty, one way or another, of 16 year. During its apparition in 1815 this comet remained a telescopic object. Its orbit was calculated by Dr. Olbers.

The sun will enter Capricornus at 3 o'clock in the afternoon on the 21st of December, when winter will

commence.

The month of November was unseasonably cold, being about 5 degrees Fahrenheit below the average, and there were several night frosts.

The average temperature for London in December, taken from observations of a period of fifty years, is 40°, while at the Land's End it is 46°, the difference being due to the action of the ocean. The average rainfall for the month in London is between two and three inches.

M. ROBIN, the celebrated French histologist, author of "The Natural History of Vegetable Parasites in Man and Animals," has just died at the age of 64.