J»v* MX t' :*-# AS122 M3P72 * FOR THE PEOPLE FOR EDVCATION 1 FORSCIENCE LIBRARY OF THE AMERICAN MUSEUM OF NATURAL HISTORY MEMOIRS AND PROCEEDINGS OF THE MANCHESTER LITERARY & PHILOSOPHICAL SOCIETY. 01 1 MEMOI RS I AJ^JE^f^^-gOCEEDINGS THE MANCHESTER LITERARY & PHILOSOPHICAL SOCIETY FOURTH SERIES FIRST VOLUME MANCHESTER 36 GEORGE STREET 1888. T. SOWLER AND CO., PRINTERS, CANNON STREET, MANCHESTER. CONTENTS. MEMOIRS. PAGE On the possible equations expressing the decomposition of Potassic Chlorate by Heat. By James Bottomley, D.Sc, B.A., F.C.S. ... 4 Pasteur and Faraday : Note on Dr. Tyndall's Introduction to the English Edition of the " Histoire d'un Savant par un Ignorant." By F. J. Faraday, F.L.S 7 On the Electrical Attraction of Quartz, &c. By Alex. Hodgkixson, M.B., B.Sc 15 The effect of the small variation of the density of the atmosphere on the ampHtude of plane waves of Sound approaching the earth. By Ralph Holmes, B.A 18 Memoir of the late Joseph Baxendell, F.R.S., F.R.A.S. By James Bottomley, D.Sc. An application of Huyghens' Principle to a spherical wave of light. By R. F. Gwyther, M.A 28 61 Notes on a Small Collection of Mosses from Mauritius. By J. CosMO Melvill, M.A., F.L.S ••• 100 On the change of incidence of Small-Pox at different ages during the years 1848-86. Parti. By R. F. Gwyther, M.A 105 A method of calculating the Electrostatic Capacity of a Conductor. By Henry Holden, B.Sc, Bishop Berkeley Fellow in Physics at the Owens College, Manchester. Communicated by Professor Schuster, F.R.S "2 On the change of incidence of Small-Pox at different ages. Part 11. By R. F. Gwyther, M.A 121 Descriptions of twenty-three new species of Hymenoptera. By P. Cameron. Communicated by Charles Bailey, F.L.S i59 A survey of the genus Cypnva (Linn.), its Nomenclature, Geographical Distribution, and Distinctive Affinities : with descriptions of two new species and several varieties. Plates I. and II. By James Cosmo Melvill, M.A., F.L.S 1S4 Vi. CONTENTS. PAGE A Catalogue of the si)ecies and varieties of Cyprrca, arranged on a new circular system in accordance with true sequence of affinity. By James Cosmo Meta'ill, M.A., F.L.S. 238 Memoir of the late Professor Balfour Stewart, LL.D., F.R.S. By Professor A. Schuster, Ph.D., F.R.S., F.R. A. S 253 m^OCEFDINGS. Bailey, Charles, F.L.S. — Obituary notices of Dr. A. de Bary, Dr. Asa Gray, and Dr. J. T. Koswell 93 BoTTOMLEY, James, B. A. , D.Sc, l-.C.S. — On an error in his paper "On the Composition of projections in Geometry of two dimen- sions'' ... ... ... ••• •■• ••• ••• ••• ••• S9 Additional Note on "The equations expressing the decomposition of Potassic Chlorate l)y heat" ... ... ... ... ... ... 9° Brothers, H. E., A.I.C, F.C.S. — Note on a Nickel Arsenide. Com- municated by Alfred Brothers, F.R. A. S 135 Dixox, Harold B,, IM.A., F.R.S. — On the Union of Hydrogen and Nitrogen ... ... ... ... .•• •.• ••• ••■ 9^ Faraday, F. J., F.L.S.— On Herons and Thrushes in the Ardennes ... i Communication from Mr. G. J. Romanes, M.A., LL.D., F.R.S., on experiments bearing on the theory of Physiological Selection ... 60 On the Perched Blocks on Norber, a spur of Ingleborough ... 98, 104 HowoRTH, Henry H., F.S.A., M.P.— On an Old Clock in the Chetham College Library 3 Kendall, Percy F.— Note on an Erratic Block observed during excava- tions for a sewer in Oxford Street, Manchester. Communicated by Thos. Kay 97 Lamb, Horace, M.A., F. R.S.— On Reciprocal Theorems in Dynamics... 27 Melvill, James Cosmo, ^LA., F.L.S.— On an original printed draft of Warren Hastings' "Defence," with manu.script annotations by the Right Hon. Edmund Burke 3 Nicholson, Francis, F.Z.S.— Herons and Thrushes in France and Belgium ... ... ... .•• ••• ••• ••• ••• ^ PiCKsroNE, ^V^L— On a portable pneumatic tool giving 5,000 to 20,000 strokes per minute, and a small steam compressed-air engine working at 5,000 revolutions per minute. Communicated by \V. H. Johnson, 15. Sc ^35 CONTENTS. Vii. PAGE Schuster, Arthur, Ph.D., F.R.S., F.R.A.S. — On some experiments by Professor Hertz, of Carlsruhe, with ultra-violet Light and the Electric Discharge 6 On researches by Professor Ilann, of Vienna, on Temperature in the centre of an anti-cyclone ... 92 Smith, James. — Note on the bi-centenary of the Principia ... ... 59 Stewart, Balfour, LL.D., F.R.S.— On Mr. Norman Lockyer's paper on the derivation of the heavenly bodies ... ... ... ... 18 Williamson, W. C, LL.D., F.R.S.— On the fossil stigmarian roots of a lepidodendroid or sigillarian tree in the Museum of the Owens College ... ... ... ... ... ... ... ... 60 Williamson, J. R. H. — On an 800-candle power Edison-Swan in- candescent lamp and a new form of American frictional electrical machine for exploding dynamite in blasting ... ... 12 1 Meetings of the Microscopical and Natural History Section : — Annual Ordinary 14, 17, 26, 88, 99 Meetings of the Physical and Mathematical Section : — Annual Ordinary ... ... ... ... ... ... ... .. 89 Presentation to Mr. William Roscoe ... Report of the Council, April, 1888, with obituary notices of Charles Moseley and John Benjamin Dancer ... ... ... .-143 List of the Council and Members of the Society ... ... ,., ... 273 139 134 138 15 ERRATA. Page line 6, 17, 15, I, — , 6, 35, 34, 36, 33, 37, 5, 42, i3» 52, 18, — , 24, ^7i, y:>. or in read on. for November 1 6th read November 15th. M ,5 >> >> j> )> for disposition read deposition. for full read first. for titles read tables. for Light read Rifle. for visible read invisible. for antozene read antozone. for RUFiPEs read Montezuma. NOTE. The authors of the several papers contained in this volume are themselves accountable for all the statements and reasonings which they have offered. In these particulars the Society must not be considered as in any way responsible. ^f2^ MEMOIRS AND PROCEEDINGS OF THE MANCHESTER LITERARY AND PHILOSOPHICAL SOCIETY. Ordinary Meeting, October 4th, 1887. Francis Nicholson, F.Z.S., in the Chair. Reference was made to the loss which the City and the Society had sustained through the death of the Society's new member, Mr. Charles Moseley, and to the material assistance which he had recently rendered to the Local Committee for the reception of the British Association in Manchester. Mr. Moseley made considerable sacrifices in endeavouring to maintain the Manchester Aquarium as a scientific institution, was instrumental in introducing and establishing telephonic communications in the City, and took an active part in organising the Manchester Jubilee Exhibition. Mr. Faraday mentioned that during a recent excursion (September) in the Belgian Ardennes he had seen a stuffed heron at Laroche, on the Ourthe, and, on inquiring if the bird was common in that locality, had been informed that it was only seen there in the winter — when it was abundant — but never in the summer months. He also alluded to the 4TH Series. — Vol. I. — No. i.— 18S7-8. 2 Herons and TJirusJies. abundance of the thrush (French "Grive"), which was served at dinner in most of the hotels, and could be purchased for five centimes (one halfpenny) each. The Chairman stated that no doubt the heron seen was of the same species as our common heron. In spring and in autumn there is a general shifting of the different species of birds going on from south to north and from north to south, not only amongst so-called migrants, but amongst species that are often considered to be residents. This movement takes place to a far greater extent than people who have not studied the subject would suspect. The common heron, or, as it is called in France and Belgium, '' Heron huppe," is no exception to this rule, for as the spring advances it proceeds further north to its breeding quarters, and returns in the fall of the year, or when the hard weather comes on, to the south of Europe. Messrs. Degland and Gerbe, in their "Ornithologie Europeenne," say: — "The common Heron Ardea cinerea^ is found throughout the year in the vast marshes of Languedoc, Roussillon, and on the banks of the Rhone near its mouth," but probably the birds that are found in these localities in summer are birds that are not breeding in that particular year. The elevation of the Ardennes is nowhere very great, the valleys are sheltered, and the winter appears to be com- paratively mild. As to the thrushes alluded to, they are most likely to be either the Fieldfare, "Grive litorne" of the French, or the Redwing, " Grive mauvis." Both these species visit the south of Europe in large flocks in the autumn from the north, where they breed in large numbers. The Redwing, Tiirdns iliaciis^ occurs during the winter and severe cold, in flocks, in company with the Fieldfare, Tiirdus pilaris, and they are much sought after for the table. The Redwing is a much smaller bird than the Fieldfare, but its flesh is more delicate in flavour. Proceedings. 3 Ordinary Meeting, October i8, 1887. Professor BALFOUR STEWART, LL.D., F.R.S., President, in the Chair. The President referred to the death of the Society's old member, Mr. Joseph Baxendell, F.R.S., F.R.A.S., for twenty- four years one of its secretaries and the editor of its publications up to his death, and stated that the Council had made arrangements for the preparation of an account of the deceased gentleman's life and work, and had passed a resolution expressing sympathy with Mrs. Baxendell in her bereavement. On the motion of Mr. H. H. Howorth, M.P., seconded by Mr. James Smith, it was resolved that a similar expression of sympathy should be forwarded from the Society. Professor SCHUSTER alluded to the death of Professor Kirchoff, of Berlin, chiefly known for his work on the mathematical basis of Spectrum Analysis, and the author of many memoirs on various subjects of Mathematical Physics. Mr. H. H. Howorth, M.P., directed the attention of the members to an old clock long preserved in the reading room of the Chetham College Library. It was presented by Nicholas Clegg in 1695, as appears from an entry in the donation book of the College. The clock has on it a barometer, which is still intact and is a very early example of the instrument. The barometer and a thermometer (now lost) are named with the clock in the notice of the gift. Mr. James Cosmo Melvill exhibited the original printed draft of Warren Hastings' "Defence," copiously anno- tated with marginal notes in the handwriting of the Right Hon. Edmund Burke, being the copy the great orator held in his hand at the time of his famous impeachment of the former Governor-General of India, in February, 1788. This 4 Dr. Bottom ley on the most interesting M.S. was rescued from destruction during a general clearing out of old papers stored in the cellars of the old East India House in Leadenhall Street, London, by Mr. Melvill's grandfather, the late Sir James Cosmo Melvill, K.C.B., F.R.S., secretary of the H.E.I.C.S. for many years, from whom Mr. Melvill inherited it. On the possible equations expressing the decomposition of Potassic Chlorate by Heat. By James Bottomley, D.Sc, B.A., F.C.S. It has long been known that potassic chlorate when heated is resolved into oxygen, potassium chloride, and a more highly oxygenated product, potassium perchlorate, the equation expressing the change being usually written 2KCIO3 = KCIO4 + 2KCI + O2. Lately the decomposition of the salt has been investi- gated by Teed, and also by P. Fraiikland and Dingwall, their results being communicated to the Chemical Society. Teed, from his results, derives the equation 10KCIO3 = 6KCIO4 + 4KCI + 3O0, and in a second communication giving the results of ex- periments wherein the salt was more gently heated, he gives as a more approximate equation 22KCIO3 = 14KCIO4 + 8KC1 + 5O2, P. Frankland and Dingwall derive from their results the equation 8KCIO3 = 2O2 + 5KCIO4 + 3KCI. The matter has also been discussed by Mills in the April number of the Philosophical Magazine. He there gives the following equation as expressing all known relations among those products : — (i) 2;2KC103 -in- 2)02 = {n + i)KCl04 + {n - i)KCl. Some years since I gave a general method for determining the coefficients in chemical equations (^Proceedings — Lit. D€coi]ipositio7i of Potassic Chlorate. 5 & Phil Soc.—Vo\. xvii.). Suppose P molecules of KCIO3 to interact and give rise to Qi molecules of KCIO4, O2 molecules of KCl, and O3 molecules of O, then we shall have the equation (2) PKCIO3 = Q1KCIO4 + QsKQ + QsOa equating the coefficients of K on each side P = Qi + Q2, the coefficients of CI when equated give a similar equation. From the coefficients of O we derive the equation 3P = 4Qi + 2Q,. Hence we have four unknown quantities and only two equations. Substituting in (2) we get (3) 2PKCIO3 - 2Q1KCIO4 + 2(P - Qi)KCl + (3P - 4Q)02 an equation containing two variables with the condition that P and Q are integers and 3P not less that 4Q. From the equation it is manifest that from the interaction of a given number of molecules of KCIO3 we may have several solu- tions of the equation : the number of solutions may be found by finding the largest integer in ^— ; an additional solution may be found if we admit = Hcos — ' (<7/ - .t) c A. set up at a region where the density is D^ the expression while the amplitude of the retrograde wave is H,/5oAXsin^" V D X where A\ is extremely small. Let us suppose that A and B are two planes of constant density at some little distance apart, and that at A, the progressive part of a wave travels towards B, through the slowly varying gas between ; then at every part of its course we have a reflected wave so that the progressive part which passes B is not exactly the same as it would have been, if the gas between A and B and beyond B had been absolutely uniform. If we were to consider, however, that the density between the planes was allowed to become uniform so that the change of density at B would be sudden, then the same wave passing A would travel unchanged to B, part being reflected there, while the progressive wave passing B would differ infinitesimally from the progressive wave passing B when the gas varies continuously. These considerations will guide us in the discussion of the problem in hand. Let .... A,_i A A^^i .... be planes of constant density, the difference of density at any two consecutive planes being excessively small, and suppose that all bodily forces producing the variation of density are annihilated, the planes being prevented from consequent motion by properly applied surface forces. Gravity is here supposed to be the cause of the variation and acts in the direction A^-i A,. 20 . Mr. Holmes on Then if P^.j Is the uniform pressure between A^.i A^ the force required per unit area on the plane A^ is P^— P, i. We may notice that P^.i is the actual pressure in the original state of the gas at some point between A^.^ A^. Let ^x be taken normal to the planes . . . A^^iA^ . . . and suppose that in some one of the compartment plane waves of sound of a given period are set up, the direction of pro- pagation being 0,t'. Let Xs be the equilibrium distance of a normal plane in the compartment A^A^+i from the equilibrium position of the plane A^, x^ + ^; 3 the disturbed position due to the wave motion^ P^, D5 the pressure and density in equilibrium, /^, p^ the pressure and density at the disturbed position of the plane x^ when there is wave motion. Then for the compartment A^A^+i we arrive at the ordinary equations of wave motion, viz. : — ae • at' D, dx. If ^^ be the distance of the plane A^ from the origin, and /, be the distance between the planes A^ A^+i, then a solution of (i.) which holds for all values oi x^ between 0 and /, may be written js = (CsCos;^/ + B,.sin«/)sin;;/(^, + x)i + (C/cos/^/+ B/sin/z/)cosw(s5 + x^ where c^^ &c., are constant between Xs = o and x^ = l^. By changing the suffixes we may write the solution for any other compartment. At the surface of separation of any two compartments, say A^+i, we have the condition of equal velocities, viz. : — A<+i\ (d\\ \ dt )x,j^x = 0 \dt)x, = l, which must hold for all values of the time. Plane Waves of Sound. 21 Substituting for \^ and f,,+i and equating coefficients of cosnt and of smnt we get Qsin;;zSs+i + C/cosw^s+i = Q-f isin/z/s-^+i + Cs4-i'cos;;/5r^,-|-i . . . (iii) and a similar equation for the V>'s. We have also another surface condition, viz.: that of pressure, which gives us for all values of the time V dxjx, = 4 V.T,-^ i/^^s+i = 0 from which we obtain Fg^CgCOsmZg+i - CJs\n?nZgj^i} = Vg+ilCg+iCOsmZt^i - C;+isin;;/^,+i} . . . (iv.) and a similar equation for the B's. Hence from these two equations (iii.) and (iv.) we can determine Cs+i] C/+i in terms of G; C/ and so in terms of C • C ' Now the constants Q+i, C/+i must be expressible as some function of the compartment to which they belong and hence must be some function of the density of that compartment. Hence since the difference of density between any two compartments is extremely small we may write ^D< +1 Where aD,+i is the small change of density, its square and higher powers being negligible. If we substitute these values in equations (iii.) and (iv.) and neglect small quantities we obtain the equations dC dC „ ^fdC dO . \ dVf^ -,, . \ ^ r[-^co?,mz - -^j^smmz j + -^^( Ccosws - Usiwnz j = U or since -j:^ occurs in each term, these may be written 22 Mr. Holmes on dC dC ^ sm?nz--r + cos7Uz-j-~ = 0 az dz ^f dC . dC\ dF,^ Ficosmz-^ - smmz-^ j + — (Ccosw^r - Csinmz) = 0. Now F = kD ; we have therefore to consider the value of the dF differential coefficient -^. dz As stated above P is the pressure at some point^between the planes A,+i A^+g in the actual state of the gas, from dF which we immediately obtain — =^D. Thus our equations for C and C become, writing y for 7/1^, . dC dC ^ cosy^sinj;^ + //(Ccosy - C'sinj) = 0, or where /i = ~. mk If in these equations we put C = r sinj/ + C0SJ1/--J- ^, ^ . dF C = rcosy - sinjK , the first is satisfied identically, while the second becomes d^F dF _; . dy^ dy the solution of which is P = e^y (^k.Q.o'-^vy + BsinrjF), where ju + v ^" - i are the roots of X^ + //jv: + I = 0 and J^ is supposed for the moment less than 4. The values of B and B' differ only from those of C and C^ by containing different constants. If then we substitute the values found in the expression for \, noticing that Plane Waves of Sound. 23 v? + j/2 = I so that we may put cos0 = \i, sinQ = v ; after a little reduction we obtain ^ = cosmx.ei^^nz [Acosntco^iymz - /3) + A' ?,m7itcos{vi?iz - /3') } + smmxei^^'^^{Aco^ntcos{vmz - /3 - 0) + A' sm?itcos{vinz -ft'- 0)} when A, A', /3, /3' are absolute constants. Now suppose that in the compartment at the origin we have the motion given by \ = llcos(7if - mx). Applying this condition to determine the constants, we obtain for the motion in a compartment distant z from the origin \ = H^^''''|cos j'W^cos [7it - mx) - ^^^^^in {nt - mx) + cot0sini^;;/5cos(;// + mx) But from the equations we get so that P = KD V D — "R /Do f / ^ \ sinvmz Thus finally we obtain - A / -^°\ cosymzcos int - mx) — ^^^^^^^sin(;// - mx) + cot0sin)'wscos(;2/+ mx) v . . . v. This solution will allow us to obtain a very good idea of the changes which a sound wave undergoes when travelling through the continuously varying atmosphere, and will serve us to show how extremely small is the error in the ordinary approximation where we suppose there is no reflected wave. Examining the solution v. we notice that it consists partly 24 Mr. Holmes on of a progressive and partly of a retrograde wave, of which the amplitude of the former is -J'ii sm^viftzY^j while that of the latter is ^V I) cotQsmv7nz. We will now show that the solution given satisfies the equation of energy. In the wave ^ = Hcos(;2/ - inx) the work transmitted across unit area in time t is W = -D,-HV. 2 ??l We will now obtain the expression for the work transmitted across unit area in time t, in the wave -v^-{ . \ co^vmzcos{nf - inx) - . sm{nt - inx) + cotO If P be the pressure and IV the variation of pressure = iH^D,^' jcosV;;/^ + sinV^^ _ cot^Osin^r;^^ + .... periodic terms \ ^H^Do- \ I + periodic terms 2 ;;/ (^ 2 2 ;;/ which shows that the condition of energy is satisfied. Let us now consider the value of the small quantity J^ and show that it is less than 4. We have mK. 27rK where v is the velocity of sound 7 is 1-410. Plane Waves of Sound. 25 h y 2-kv y. number of vibrations per second. If we take the number of vibrations to be 550 per second, and the velocity of sound to be about 1 100 feet per second, we obtain 32-2 X 1-41 so that thus •000012, 27r X iioo X 550 •000006, v= yj \- (•000006)'^' cot0= - '000006, -T-^, - I + ~(-ooooo6)l sin^f^ 2^ From these results we draw the following conclusions : that when plane waves of sound are travelling through the atmosphere and partially reflected at every part of their course, the amplitude of the progressive part differs by a few thousand-millionths of what it would have been if we supposed that the wave progressed without the slightest reflection ; and if, instead of considering the reflected waves which occur at every part of the course for a number of wave lengths, we considered the reflected wave as being caused by a sudden change of density, then the amplitude of the retrograde wave would be about a millionth part of the progressive wave. The method employed above seems unnecessarily arti- ficial, but it has enabled me to obtain a result in some subsequent work which, I believe, is not only new, but correct, viz., that when the atmosphere is also supposed to be in a state of " convective " equilibrium the amplitude of y + I r a descending wave varies inversely as the power of the density. 26 Proceedings. MICROSCOPICAL AND NATURAL HISTORY SECTION, Ordinary Meeting, December I2th, 1887. Professor Williamson, LL.D., F.R.S., President of the Section, in the Chair, Mr. Edward Pyemont Collett, F.E.S., was elected an associate. Mr. P. Cameron, F.E.S., exhibited, — a fine collection of Indian Hymenoptera ; Mr. Sington, — Resin containing insects, from Zanzibar; Mr. H. C. Chad WICK, — Two Armed Bull-heads, Aspi- dophonts EtiropcetiSy taken by him in the dredge in the Menai Straits ; also, under the Microscope, a stained speci- men of the Medusa, Oceanea conica. The President showed living plants of Salaginella pilifera, and Salaginella lepidopJiylla, and described their specific differences and fructification. Proceedings, 27 Ordinary Meeting, December 13th, 1887. Professor OsBORNE Reynolds, LL.D., M.A., F.R.S., Vice-President, in the Chair. The Chairman referred to the death of the Society's honorary member, Mr. J. B. Dancer, F.R.A.S., and Mr. Faraday (one of the Secretaries) reported that he had been waited upon by Mr. Abel Heywood, Junr., and Mr. H. H. Howorth, M.P., with a request that he would bring to the notice of the Society the desirableness of an effort being made to obtain a grant from the Civil List for Mrs. Dancer. Thereupon — It was moved by Mr. R. F. Gwyther, M.A., seconded by Mr. Harry Grimshaw, F.C.S., and resolved, "That the Officers of the Society be requested to consider, and, if possible, to further the application for a grant from the Civil List in behalf of the widow of the late Mr. J. B. Dancer." Professor HORACE Lamb, M.A., F.R.S., made a short verbal communication on reciprocal theorems in dynamics. He called attention to a theorem recently given by Helmholtz, which appears to include as particular cases almost all the reciprocal relations as yet discovered in Dynamics, and gave several illustrations from Optics and Acoustics. In particular he referred to the principle of acoustic reversibility formulated long ago by Helmholtz, to the effect that if A and B be any two points in a homo- geneous atmosphere at rest, the sound-intensity at B due to a source at A is equal to the intensity at A due to an equal source at B. The case when the air is in motion does not come under the principle as here stated ; and in fact if B be to the leeward of A, the intensity is greater in the first case than in the second. The theorem referred to shows, however, that the reciprocity still holds, provided that when we transfer the source from A to B we also reverse the wind. 28 Dr. Bottomley on the late Memoir of the late Joseph Baxendell, F.R.S., F.R.A.S, By James Bottomley, D.Sc. Joseph Baxendell was born April 19th, 1815, at Bank Top, Manchester. He was the son of Thomas Baxendell, an intelligent man, who by his own exertions raised himself from humble life. The family consisted of six sons and two daughters. Of his mother, whose maiden name was Mary Shepley, it is related that she had a strong love of observing the heavenly bodies, knowing well the planets, and many of the principal constellations ; to this source probably may be traced Mr. Baxendell's life-long devotion to astronomy, early impressions giving to the mind, while yet supple and tender, a bent which remains to old age. His early years were spent at his parents' farm at Smedley, but agriculture was not his destiny, and, later on, a churn from the old farm served him as the most suitable round table on which to grind and polish specula for telescopes for himself and some early scientific friends. He was educated by Mr. Whalley, of Cheet- ham Hill, a man of some scientific attainments. He proved himself a rapid learner, and soon acquired all that his teacher could impart ; to a large extent we may consider him as self- taught. If there had been then the opportunities now offered by the city for instruction in experimental science, possibly there might have been developed a capacity for experimental enquiry which would have been serviceable in some branches of his work. He does not seem to have devoted much time to experiment, and he was destined to develope into the accurate observer of phenomena, and the deduccr of laws from laborious calculations. From his bent for mathematics, one may reasonably infer that a brilliant mathematician would at this time have found in him an apt pupil, and yet again, a possible advantage might not have been without some detriments, and excursions into the domains of pure Joseph Baxeiidcll, F.R.S. 29 mathematics would have left less time for astronomy and meteorology. We are liable to imagine that a man who has done well, would have done better under more favour- able circumstances in his early career, but this is far from certain, and of one who has won for himself an eminent position with little extraneous assistance, we may with good reason say that it was best as it was. His constitution in early life was delicate, frequent visits to Southport with his mother for the sake of health led also to a love for a sea- faring life ; at first the fishing boats gave him an opportunity of gratifying his enthusiasm ; afterwards, when about 14 years old, he embarked on board the ship Mary Scott, bound for Valparaiso. This step was taken in the hope that the voyage would invigorate his delicate constitution. Although so young, his excellent seamanship soon won the entire confidence of his Captain. It was his fortune to be a witness of the extraordinary display of meteors in 1833 ; he was well adapted to be the spectator of such a magnificent scene, being not wholly lost in admiration, but seeking to determine the radiant point from which they diverged. He also, while out at sea, experienced the shock of the earthquake in 1835, which was attended with such disastrous results to the Pacific coast of South America. He made several voyages, and when he retired, it was with no disgust of a maritime career, indeed in his old age, he would still speak with enthusiasm of the sea and the sailor's life. After returning to Manchester, he was for some time engaged in assisting his father in his business. For some years he resided at Stocks Street, Cheetham, and afterwards at Crescent Road, Cheetham Hill. Here he was not far from the Observatory belonging to his friend Robert Worthington, situated in the pleasant park-like grounds attached to Crumpsall Hall. An accident to his right eye debarred Mr. Worthington from using his own Observatory ; Mr. Baxendell had the privilege of using it, and the excel- 30 Dr. Bottomley on the late lent work done therein, until its removal in 1869, won for it a distinguished place amongst private observatories, and engaged Mr. Baxendell in correspondence with the most eminent astronomers both in this country and abroad. Amongst other astronomical friends with whom he corres- ponded was Mr. Norman Pogson, Government Astronomer of Madras, and this connection became a closer one by the marriage of Mr. Baxendell with Mr. Pogson's sister Mary Anne in 1865 ; the issue of the marriage was an only son. His quiet orderly life offers little to be recorded. In his own town he was not widely known, nor did he ever seek to become widely known ; indeed he furnishes a fresh instance of a peculiarity of scientific life in Manchester, that is the seclusion, almost bordering upon obscurity, of some of its most eminent men. Of Dalton it is stated by one of his biographers, " As is usually the case, on the death of an eminent man, the first proof is furnished to many persons that he was once alive." Personal intercourse with Mr. Baxendell would leave the impression of amiability of disposition, and of a simplicity of character which has often been found associated with scientific eminence. Sometimes his communications would involve him in argument ; on such occasions his views, when correct, were stated so quietly, and with such an absence of elation, that an adversary felt no wound. With regard to new theories, he was sometimes slow of conviction ; no doubt the very nature of his studies had impressed upon him the extent of human fallibility, and the necessity of sifting evidence. He would slowly give way, however, when figures were brought against him, for then you had him on his own ground. He was always pleased to be of service to any member of the Society, and he took an active and influential part in obtaining the appointment of Government Inspector of Alkali Works for one of our late members. Joseph Baxendell, F.R.S. 31 In the Royal Society's list of scientific papers his name will be found associated with numerous communications ; some of these were published in the Monthly Notices of the Royal Astronomical Society, some in the Astronomisdie Nachrichten^ but the greater and most important portion of his work was given to our own Society. The earliest paper mentioned in the list, is one on the variability of X Tauri {Astronomical Society MontJdy Notices^ ix., 1848-49). The list also includes a joint note by J. Baxendell and H. E. Roscoe, on the relative intensities of direct sunlight and diffuse daylight at different altitudes of the sun {Proceedings of the Royal Society , vol. xv.) ; during the latter part of his life he also published some articles in the Observatory and Liverpool Astronomical Society's Journal. He was elected a member of this Society in 1858, and a member of the Council, January 25, 1859, in place of the late Rev. H. H. Jones ; he was appointed secretary and editor of the Society's publications in 1861 ; the secretary- ship he retained until 1885, when, to the regret of the members, he retired on account of ill-health ; for one year he was a vice-president. He was also an active member of the Physical and Mathematical Section, being one of its founders in 1859, the original members being Robert Worthington, J. W. Long, E. W. Binney, Joseph Baxendell, J. B. Dancer, S. W. Williamson, W. L. Dickenson, G. C. Lowe, Joseph Sidebotham, Thomas Carrick, George Mosley, and Thomas Heelis. This list of names reminds us how many have been the changes in the Society since 1859; of ^^ mentioned not one now survives. Most of Mr. Baxendell's papers were in the first instance communicated to this section ; the quiet social character of the meetings seemed quite in harmony with his retiring disposition ; first there was the half-hour spent in pleasant conversation over tea, and, when the cloth was drawn, the half-dozen members, or thereabout, who ordinarily 32 Dr. Bottomley on the late composed a meeting, would draw up to the green baize table, with the President of the Section at one end, a cheer- ful fire would give a pleasant glow to the old council room, and four wax candles, if they could not compete with modern methods of illumination, were not without a certain charm, reminding us that we belonged to an old society, and recalling the days of Mainwaring, Massey, Percival, Henry, Dalton, and other old worthies of the Society. To such an audience Mr. Baxendell would read his papers in a low-toned voice but marked with earnestness. Of this section he was elected president ten times. He always spoke in very high terms of the Literary and Philosophical Society, he would even declare that no other Society had done so much useful work, an opinion which might appear extravagant to a stranger unacquainted with its past history ; to form some estimate of it, let us reflect that systematic chemistry, which has been such a powerful agent in increas- ing the resources of civilized life, had its origin here, while the text books of the engineer bear testimony to the useful work of Hodgkinson ; if living names were mentioned, they would supply a strong proof of the useful work of the Society, and so lend confirmation to Mr. Baxendell's opinion. This character of use is also stamped on his own work; he took a warm interest in the plan of supplying storm warnings, and made a vigorous protest when the Board of Trade announced an intention of discontinuing them ; he was also anxious to obtain definite information of the influence of meteorological conditions on public health. His warning of the dry summer of 1868 was very serviceable to the Manchester Corporation Water Works in regulating the supply of water. On another occasion his warning at Southport,to take precautionary measures against an epidemic, was followed by an outbreak of small-pox. The interest which he took in this Society was also testified by his assiduous attention to the duties of Secretary ; his JosepJi Baxendell^ F.R.S. 33 intimate knowledge of the rules made him a very valuable officer of the Society; of the strict observance of these rules he was very tenacious, both with regard to himself and others. He was also opposed to any popular administration of the Society, which under adelusiveappearance of prosperity would contribute no real advantage to the purposes for which it was founded. His devotion to astronomy and meteorology gave a decided bias towards these subjects in the work and discussions of the Society ; he was also the means of bringing to it the work of other meteorologists, amongst whom may be named the late G. V. Vernon, the Rev. J. C. Bates (of Castleton), Dr. Black, and the Rev. T. Mackereth. His activity in the interests of the Society continued until a few years back, when he was afflicted with a disease in the lower jaw, attended with a series of painful abscesses ; in addition he was at times troubled with a difficulty of breathing. On a partial recovery, he attempted to resume his old regularity of attendance, and would even venture out on cold wintry nights to do so; but his appearance made it painfully evident to a spectator that his constitution was thoroughly under- mined. His latest residence was at Southport ; here he was appointed superintendent of an observatory in Hesketh Park, fitted up and presented by Mr. John Fernley, formerly of Manchester. In his private observatory at Birkdale he resumed his astronomical work, in which he had the valuable assistance of his son, who has had the advantage of his father's training. He was also meteorologist to the Corporation of •Southport; he had been since 1859 astronomer to the Corporation of Manchester, succeeding the Rev, H. H, Jones. He was elected a Fellow of the Royal Astronomical Society in 1858, and a Fellow of the Royal Society in 1884. Of foreign societies, he was a corresponding member of the Roy. Phys. Econ. Soc, Konigsberg, and Acad. Sci. and Lit., Palermo. Before proceeding to an account of his work in this C 34 DR- Bottomley 071 the late Society, it may be mentioned that in later life he took an intense interest in the history of the Great Pyramid ; he seemed to think that the builders of it were under some kind of inspiration, and that in the dimensions of certain passages and chambers were contained the most recent and accurate measurements made in physical astronomy, and also some of those numbers which mark epochs in religious history. Some of his calculations were given in a paper read before the Physical and Mathematical Section, but not published, possibly because he did not think it would be suitable for the Society, perhaps because he wished to subject it to further consideration. On enquiry, I am informed that his interest in this work, and in the fulfilment of prophecy, continued to the last. Some of his results were contributed to the International Standard^ published by the International Institute for Preserving and Perfecting Weights and Measures, Cleveland, Ohio ; some of his calculations in connection with this subject remained unfinished. He closed his mortal life October 7th, 1887, in the 73rd year of his age. The following opinion of his position as a meteorologist, by one who has laboured in the same field, will form a suit- able preface to an account of his work given to this Society. In an article in Natitre^ Dr. Balfour Stewart states : — '^Baxendell's contributions to meteorology are very impor- tant, and in one branch of the science he may claim to be the pioneer. In 1871, from an analysis of eleven years' observations of the Radcliffe Observatory, Oxford, he came to the conclusion that the forces which produce the move- ments of the atmosphere are more energetic in years of maximum than in years of minimum sun spot activity. This conclusion has now been confirmed in various directions by other observers. We have heard it objected that Baxendell generalised from a comparatively small number of observa- tions ; but in a question like this such a procedure is essential Joseph Baxendell, F.R.S. 35 to the pioneer. His task is to deduce, with a mixture of boldness and prudence, something of human interest out of the observations already accumulated, and thus to stimulate meteorologists not only to go on with their labour, but to cover more ground in the future than they have covered in the past. Baxendell's procedure in this respect has been abundantly fortified by the fact that many other men of science are followers in his footsteps." His first communication was a note on Donati's comet, October 19th, 1858 ; during this Session (1858-59) he also contributed a note "On Solar Spots." In Session 1859-60, "On the Barometric Pressure on November loth, 1859"; "Direction of a Storm Indicated by Meteors"; "November Wave of Barometric Pressure"; "Rotation of Jupiter." The appearance of several spots induced him to make a series of observations with a view of obtaining a re-determination of the planets' period of rotation, and to test the conclusion drawn from the observations of Cassini, Sir W. Herschel, Schoeten, &c., to the effect that different spots have different periods of rotation. His own observations confirm the con- clusion drawn from earlier observations, that the different spots have different periods of rotation ; Cassini's observa- tion that spots near the equator move more rapidly than those more remote is not confirmed ; the rotation of the planet cannot with any certainty be deduced from the motion of the spots. — "On a new variable star, R Sagittae" ; "Observations of the Zodiacal Light"; "Remarks on the Theory of Rain." After discussing the views of Professor Phillips, from a consideration of the amount of rainfall at different elevations above the ground, he concludes that only a very small portion of the total augmentation of a rain drop can be due to the condensation of vapour upon its surface, and that by far the greater portion must be due to the disposition of moisture which has already lost its latent heat or heat of elasticity, and which is, therefore, not in the S6 Dr. Bottomley 07i the late state of a true vapour, although on the other hand the invisi- bility in the atmosphere under ordinary circumstances, in the form of cloud or fog, renders it difficult to suppose that it can be in the ordinary liquid state. If the vapour brought by a rainy wind retains its latent heat up to the moment that actual precipitation of rain takes place, the sudden disengagement of the heat, although occurring in the higher regions of the atmosphere, ought to have a very sensible effect in raising the mean temperature of rainy days, but no such effect is produced. To account for the enormous quantity of heat given off by the vapour which is condensed in the atmosphere, he thinks that it is probable, that air nearly saturated with vapour has a greater power of radiating heat than dry air. The unusual transparence of the atmosphere often observed immediately before, and even during showers, is probably due to its being charged with vapour which has lost its latent heat. " Observations of the Oblique Belt on Jupiter." Session 1 860-61. — " Phenomena of Solar Spots"; "On a System of Periodic Disturbances of Atmospheric Pressure in Europe and Northern Asia." In an enquiry of this kind he states that determinations of the statical element of mean pressure are obviously of very limited use, but notwithstanding the importance of the subject, meteorologists have hitherto generally neglected to ascer- tain even approximately the value of the dyna7nical element as represented by the extent and frequency of the oscillations of the mercurial column. He gives tables showing the mean monthly and annual sums of the oscilla- tions of the barometer at seven stations in Europe and six in Asia, derived from observations extending over periods varying from six to fifteen years. He remarks that the full application of the method employed appears to have been made by Dr. Dalton in his meteorological essays. — '' Note on the Phenomena of Solar Spots." From some data Joseph Baxendell, F.R.S. 37 of Dr. Wolfs by the method of least squares, he deduces a mean period of 11 '086 years. The mean epoch of mini- mum frequency being 1732-96. — "Rain near Whitehaven" : "Luminous Fogs"; "On the Irregular Oscillations of the Barometer at Lisbon." From the titles it appears that the maximum amount of oscillation occurs in January and the minimum in July, precisely as in the British Islands, and therefore agreeing with the law of disturbance announced by the author in a former paper. Session 1861-62. — " Observ^ations of Comet i in 1861"; " Remarkable Solar Spot"; "Rain Following Discharge of Ordnance." In this note he refers to the disputed point whether in a thunderstorm a discharge of lightning is the cause or the consequence of a sudden formation of a shower of rain. — " On the Influence of the Seasons on the rate of decrease of the temperature of the atmos- phere with increase of height in different latitudes in Europe and Asia." In this paper he states that from numerous observations made at elevated stations in Europe and India it has been concluded — ist, that the general rate of decrease of the temperature of the atmosphere with increase of height, is least in low, and greatest in high latitudes ; and, 2nd, that the rate of decrease is greatest in the summer and least in the winter months. Some of his results, obtained in the course of an investigation of the relations which exist between the falls of rain and changes of barometric pressure, and of the decrement of temperature of the atmosphere in different localities, led him to doubt the general correctness of the second of these conclusions, and he therefore examined all the observations that were accessible to him that seemed likely to throw any light on the subject ; he obtained some results which seem to prove the existence of a belt in the temperate latitudes of Europe and Asia, in which the decrease of temperature for a given ascent in the atmosphere is greatest in the winter 38 Dr. Bottomley on the late months, while at stations north or south of the belt, so far as observations have yet been made, the decrease is greatest in the summer months. This belt passes over Portugal, Spain, Sicily, Southern Italy, the Caucasian provinces and Southern Siberia. He also calls attention to some results which seem to indicate that the annual rate of decrease of temperature on ascending in the atmosphere is subject to a periodical change. He remarks that the epoch when the rate of decrease was at a maximum, as shown by the Geneva and Great St. Bernard observations, corresponds exactly with the epoch of minimum magnetic disturbance as determined by General Sabine from observations made at the Colonial Observatories and at Pekin ; and it is probable that there is also a close correspondence between the periods of the two phenomena. In conclusion, he thanks Mr. Vernon for his assistance, and adds that without the means of reference afforded by the many valuable volumes of meteorological observations now in the Society's library, it would have been quite impossible to have undertaken an enquiry of this nature. — " Observations of Saturn." He finds that the plane of the ring is not parallel to the dark belts on the body of the planet. — " On the relation between the decrement of temperature on ascending in the atmosphere and other meteorological elements." From a discussion of the monthly results of the observations made during the years 1848-58 at Geneva and on the Great St. Bernard, given by Mr. Vernon in his paper " On the Irregular Barometric Oscilla- tions" at those places, he concludes — ist, That on the average of the year a decrement of temperature below the mean is accompanied by a rainfall and amount of barometric oscillation beloiv the mean, and by a mean temperature and barometric pressure above the mean. 2nd, A decrement of temperature above the mean is accompanied by a rainfall and amount of barometric oscillation above the mean, and by a mean temperature and barometric pressure below the Joseph B ax end ell, F.R.S. 39 mean. 3rd, A decrement of temperature above the mean for the season is due to a cooling of the higher strata of the atmosphere, and not to a heating of the lower strata. 4th, The production of rain is attended with a diminution of the general temperature of the atmosphere, the diminution being greater in the higher than in the lower strata. It also seems probable that one of the essential conditions in the formation of a rotatory or cyclonic storm is a greater dif- ference of temperature than usual between the successive strata of the atmosphere at the point where the storm originates. Sessio7i zc^^^-d-j.—" Remarkable Atmospheric Phenomena"; " On a variable star." Notice of a variable star near the nebula, discovered by Mr. Hind in 1852 in the constel- lation Taurus, but which had now disappeared. " Oscillations of Temperature at Greenwich"; "Iris Diaphragm"; On a new Variable Star T Aquilee" ; "On a Periodic Change in the magnetic condition of the earth and in the Distribution of Temperature on its surface." The irregularities observed in some of the variable stars led him to suppose as highly probable that the light of the sun, and also its magnetic and heating power, might be subjected to changes of a more complicated nature than has been hitherto supposed, and that beside the changes which are indicated by the greater or less frequency of solar spots, other changes of a minor character, and occurring in shorter periods, might also take place. For magnetical observations he selected those made at St. Petersburg, the most northern station at which hourly magnetical observations have been made for any lengthened period. An examination of the magnetic declinations for 1848 indicated changes of activity taking place in a period of 3 1 days. This period would not apply to the observations of succeeding years, and he was led to think that it might be variable in different years. For 1856 he got a period of 23 days, for 1859 a period of 32 40 Dr. Bottomley on the late days. These results suggested the idea that the variable period thus found was in some way connected with and dependent upon the great solar spot period, the minimum value occurring in the year of minimum frequency of the solar spots and the maximum values in the years when the spots were most numerous. Several series of thermo- metrical observations were now examined for indications of periodical changes in the element of mean daily tempe- rature, and it was found that they exhibited with unexpected distinctness changes in the element, occurring also in a variable period, the range of variation, however, being somewhat less than in the case of the magnetic element, although the times of maximum and minimum were almost exactly the same. The maximum and minimum values were respectively 31 and 23^^ days. He also refers to another period having a mean duration of rather over eighteen months first observed in discussing the Greenwich magnetical observations for the years 1848 to 1859. In this paper he regards all the movements of the magnet, whether large or small, as having a common origin. General Sabine separates the larger movements from the gross mass and treats them as extraordinary disturbances. With regard to the variability of the short period, he thinks that the facts would perhaps be best explained by supposing (i) that a ring of nebulous matter exists differing in density or constitution in different parts, or several masses of such matter forming a discontinuous ring, and circulating round the sun in a plane nearly coincident with the plane of the ecliptic, and at a mean distance from the sun of about one- sixth of the radius of the earth's orbit ; (2) that the attractive force of the sun on the matter of the ring is alternately increased and diminished by the operation of the force which produces the solar spots being greatest at the time of minimum solar spot frequency, and least when the spots are most numerous ; (3) the attractive force being variable, the Joseph Baxendell, F.R.S. 41 dimensions of the ring and its period of revolution round the sun will also vary, their maximum and minimum values occurring respectively at the time of maximum and mini- mum solar spot frequency. The matter of the supposed ring may be diamagnetic and, being much nearer to the sun than any of the known planets, of much greater bulk and lightness, and being subjected to a much higher tempe- rature it will be very sensibly affected by the changes which take place in the magnetic condition of the sun, and when interposed between the sun and the earth it may act not only by reflecting and absorbing a por- tion of the heat and light which would otherwise reach the earth, but also by altering the direction of the lines of magnetic force ; we may also fairly conclude that the action of the supposed ring of nebulous matter is principally of a magnetic, and but slightly of a thermal character. From the max. and min. values of the temperature period the greatest and least values of the sidereal period of revolution of the ring will be 29*12, and 22*08 days respec- tively. From these numbers we find that the greatest distance of the ring from the sun is 0*185, the radius of the earth's orbit being taken as unity, the least distance 0*154, and the mean 0*169. The greatest attractive force of the sun on the ring being taken as unity the least will be 0*619 — the difference, he thinks, may be taken as a measure of the force concerned in the production of the solar spots. He then refers to Leverrier's observations on the motion of Mercury, leading to the view that there was a disturbing body circulating round the sun within the planet's orbit, and that the mass consisted of a ring of small bodies ; the mean distance which Leverrier regarded as the most prob- able is precisely that which the author has found for the ring of nebulous matter whose existence he has assumed. "This unexpected and unlocked for agreement, between results arrived at from considerations and by methods so 42 Dr. Bottomley on the late totally different, seems to establish the existence of this ring- with quite as much certainty as the results of the profound researches of Adams and Leverrier established the existence of Neptune before that planet had been actually seen ; this ring, however, owing to its proximity to the sun may never be seen, and like the dark companions of Procyon and Sirius it may be only known to us through its action on the other bodies of the system of which it forms a part. Should future researches place its existence beyond doubt, this will, it is believed, be the first instance in which the conclusions of physical astronomy have been confirmed by the results of an investigation of magnetical and meteorological phenomena." " On the Velocity of Light Balls." Session 1 86^-6 j. — "Earthquake of September 25th, 1864" ; " Note on a New Variable Star near the Greenwich Variable, No. 1773 of the Twelve Years' Catalogue"; "Note on the Period and Changes of the Greenwich Variable in Vulpecula, No. 1773 of the Twelve Years' Catalogue" ; "Observations of an Auroral Arch " ; " On the Thermometer Constructed by Dr. Dalton"; "Note on Mr. Bates' Rain Guage and Anemometer Observations." Session i86j-66. — " Auroral Phenomena, October 9th and 26th, 1865 "; "On a Probable Cause of Cattle Disease"; " Note on the Variable Star S Delphini " ; "On Meteors"; " Note on the Variable Star T Aquilae " ; " Note on the Cattle Plague"; "Storm Warnings in India"; "Note on the Variable Star S Coronas"; "On the Determination of the Mean Form of the Light Curve of a Variable Star"; " On the Fall of Rain During the Different Hours of the Day as Deduced from a Series of Observations made by the Rev. J. C. Bates, of St. Martin's Parsonage, Castleton Moor." " On a New Variable Star, R Crateris." Session i866-6y. — "Observations of the Eclipse of the Sun, October 8th, 1866, at Mr. Worthington's Observatory, Joseph Baxendell, F.R.S. 43 Crumpsall"; "Obsen^ation oftheMeteoric Shower, November 13-14, 1866." His observations were directed principally to the determination of the time of maximum frequency, and the position of the radiant point ; he also made an attempt to estimate roughly the relative number of meteors of different magnitudes. In this paper he goes on to say, " As I had the good fortune to witness the great meteoric shower which occurred on the morning of the 1 3 th November, 1833, I may state that the late display was far inferior to it both in the number of meteors seen, and in the brilliancy of the larger ones, and I am therefore inclined to think that a much finer display may be expected to occur in November next. At the time of the 1833 great shower I was at sea off the west coast of Central America, and although then I knew little about meteors, and the idea of a radiant point had not, so far as I am aware, occurred to any astronomer or meteorologist, the tendency of the great majority of the meteors to diverge from a particular region of the heavens was so strongly marked that it at once engaged my atten- tion, and I find, on referring to my notes, that I fixed the central point of this region in the constellation Cancer, a few degrees east of the stars c and y, and not in Leo as observed by Professor Olmsted and others in the north- western portion of the North American Continent. A great number of the meteors however had other radiant points, and some of the finest moved in long horizontal arcs, or in a direction nearly perpendicular to that of the main stream." — " Observations of the New Variable Star T Coronae." This star was remarkable for the great and rapid changes In the intensity of its light. When first observed by Mr. Baxendell on May 15th Its Intensity was estimated to be 331*2, the intensity of the light of a star of the loth magnitude being taken as unity ; by June 1 6th It had sunk to 17 ; it is probable that its intensity on May 12th when it was first seen could not be less than 912-1. An inspection of the curve 44 Dr. Bottomley on the late of intensities suggests strongly the idea that a force of an explosive character, such as could result only from the action of highly elastic gaseous matter, had been in operation to produce the sudden increase and subsequent rapid diminu- tion of brightness which had taken place ; but as some of the well-known periodical variables exhibit an equal and even a greater rapidity of change, this view cannot at present be received with much confidence; and notwith- standing the remarkable and highly interesting conclusions which Mr. Huggins and Dr. W. A. Miller have drawn from the results of their spectroscopic observations of this new variable, we are constrained to admit that the cause of variability is still involved in the deepest mystery. — " On the Recent Suspensions by the Board of Trade of Cautionary Storm Warnings," — a protest against the action of the board in suspending Admiral Fitzroy's system of storm warnings. — "Observations of the Occupation of Aldebaran by the Moon, January i6th, 1867"; "Elements of the Variable Star R Persei"; "On Dr. Buys Ballot's Weather Signal"; " On Storm Warnings," — a note expressing dissatisfaction with the Board of Trade's proposed substitution for the storm warnings." — " Observation of the Eclipse of the Sun, March 6th, 1867." Session i86y-68. — " On Solar Radiation." The obser- vations employed in this paper were those made at the Radcliffe Observatory, Oxford, from 1859 to 1864. From these numbers and the curves deduced he draws the follow- ing conclusions: ist — That the calorific intensity of the sun is subject to periodical changes, the maxima and minima of which correspond respectively with those of solar spot frequency. 2nd — That the intensity of a ray of direct sun- light on its arrival at the earth's surface in the latitude of Oxford is greater in April and September than in June, when the sun's meridional altitude is greatest. 3rd — That the curve representing the mean monthly values of solar JosepJi Baxcndell, F.R.S. 45 radiation on cloudless days, has its time of maxima and minima corresponding with those of the curve representing the mean monthly diurnal ranges of the magnetometer. 4th — It seems probable that the heating rays of the sun consist of two kinds differing considerably in intensity, and being subject to periodical changes, the times of maximum of one kind and those of minimum of the other, corresponding respectively to the time of maximum frequency of solar spots. 5th — That the oscillations of mean daily tempera- ture are intimately connected w^ith the changes which take place in the earth's horizontal magnetic intensity. The results derived from the Greenwich observations he states to have been anomalous and unsatisfactory. — " On Solar Radiation, Part II." He applies to his first paper a correction for the difference of meridian altitude of the sun in the different months of the year. He also discusses some of Mr. Mackereth's observations at Eccles in connection with the subject. From his results he derives the following conclusions : ist — The power of the atmosphere to absorb the heating rays of the sun is much greater in the summer than in the winter months, and depends apparently upon the amount of aqueous vapour which it contains. 2nd — Clouds and haze are less prevalent during the day, or their power to intercept the heating rays of the sun is less active in the spring and autumn than in the winter and summer months. 3rd — Observations of solar radiation made with a black bulb thermometer to be of value ought to be taken with the radiation thermometer placed at the same height above the ground as the shaded maximum thermometer with which it is compared ; but while freely exposed at all times to direct sunlight, it ought to be protected as much as possible from disturbing influences. 4th — Solar radiation observations made on a plan similar to that adopted at Oxford, show that the calorific intensity of the sun's light continued to diminish during the years 1865-66, when the frequency of solar spots 46 Dr. Bottomley on the late was also diminishing, thus giving additional weight to the probability that changes in the heating power of the sun's rays are intimately connected with variations in solar spot frequency. — " On the Supposed Influence of the Moon on the Temperature of the Atmosphere." A discussion of a paper contained in the monthly notices of the Royal Astronomical Society, entitled " Inductive proof of the Moon's insolation," by J. Park Harrison, M.A. After an examination of the evidence he comes to the conclusion that Mr. Harrison's results cannot be regarded as a proof of the moon's insolation ; or that it has any sensible effect upon the temperature of the atmosphere near the surface of the earth. Session i868-6g. — "Observations of Atmospheric Ozone." He thinks it probable that the amount of ozone near the earth's surface is dependent upon the height at which clouds are formed in the atmosphere. He gives his opinion with hesitation, and states that the subject is one in which the meteorologist requires the aid of a chemist, and that the method now employed for detecting the presence of ozone in the atmosphere and measuring its amount is very imper- fect, and the causes of its frequently sudden development, and almost equally rapid disappearance, are at present involved in mystery. In a subsequent paper the late Pro- fessor Jevons states, "During my own observations on ozone I felt strongly the imperfection of the method of measure- ment alluded to by Mr. Baxendell, and I thoroughly agree with him that the mysterious variation of ozone will not be understood until not only the quantity of air brought into contact with the paper be measured, or regulated, but the varying source and magnitude of supply be considered." — "On the Lunar Spot IvAai/, IVA239"; "Observations of the Transit of Mercury"; "The Bleaching Action of the Atmosphere on Ozone Test Papers on the Day of the Colliery Explosion at Hindlcy Green;" "On a Diurnal JosepJi Baxendell^ F.R.S. 47 Inequality in the Direction and Velocity of the Wind, apparently connected with the Daily Changes of Magnetic Declination." The observations made use of in this paper are those of the Radcliffe Observatory, Oxford, from 1859 to 1865. He finds that about 7 a.m. a force, which has been almost if not quite inoperative during the previous ten hours, begins to act on the wind from a westerly direction, and gradually but rapidly increasing in intensity, produces its maximum effect between i and 2 p.m. ; it then gradually diminishes, and finally ceases to act about 9 p.m. The intensity of the force, as measured by the changes which it produces in the direction and velocity of the wind, is at its mean value during its increase at about 9.32 a.m., and during its decrease at about 5.12 p.m. Now these times correspond very nearly with those at which the magnetic declination is at the mean for the day, as determined from the Greenwich magnetic observations. He also finds that the effect of this additional force was to impel the air through a distance of 1 6*3 miles in a direction almost perpendicular to the mag- netic meridian. His results appear to show that the greatest easterly deflection should be taken as the direction of the true magnetic meridian, and that the daily oscillations are due to one disturbing force only, which, when in operation, acts always in the same direction. One may naturally feel surprised, on reading this paper of Mr. Baxendell's, to find that two phenomena so varied in character have a connec- tion ; the winds we have long been accustomed to regard as a type of fickleness, while the magnet has furnished a popular emblem of constancy. — "On the Fall of Rain at Different Periods of the Day in connection with the Diurnal Changes of Magnetic Declination." In an earlier paper, on some rainfall observations made by the Rev. J. C. Bates, Mr. Baxendell had pointed out that the curve which represented the daily variations of rainfall had well marked points of imilarity to that of the daily variations of magnetic declina- 48 Dr. Bottomley on the late tion. In a paper read before the Meteorological Society, November 20th, 1867, the President (Mr. Glaisher) states : — "There is a kind of agreement between the curve of frequency and that of the magnetic variation ; but in comparing it with that of the amount of rain there is nothing similar in the two curves, and therefore there does not seem to be any connection between the diurnal movements of the declina- tion magnet and the diurnal fall of rain." Mr. Glaisher used the Greenwich observations. Mr. Baxendell maintains that the Greenwich observations, when carefully examined, and discussed, lead to the same general conclusion which he had formerly announced, that a connection exists between the daily variation of the rainfall and the daily movements of the declination magnet. — " On the Aurora of April 15th, 1869." Session i86g-yo. — "On the Influence of Changes in the Character of the Seasons upon the Rate of Mortality." From an examination of the rates of mortality in Lanca- shire, Cheshire, and the West Riding given in the annual report of the Registrar General, he finds that the average rate was decidedly greater during five years of dry springs and summers, with wet autumns and winters, than during eight years when the seasons were of an opposite character, the mean amount of increase being 9-1 per cent, which in Lancashire alone represents an increase of more than seven thousand in the total number of deaths in one year. The general results of his investigation he briefly recapitu- lates as follows : ist — That the influence of meteorological causes is much greater than that of any other recognised influence. 2nd — That the class of diseases which is most affected by meteorological changes is Class I. (zymotic diseases). 3rd — That the relative increase in the number of fatal cases of disease at different ages in unfavourable seasons, is greatest between the ages of 25 and 75 years, or amongst those classes of the community which are most Joseph Baxendell, F.R.S. 49 exposed to the vicissitudes of weather. 4th — That the sanitary measures which have been carried out during the last fifteen or twenty years by Boards of Health, Health Committees, and Officers of Health have produced no perceptible improvement in the state of the public health, nor checked the growing increase in the rate of mortality, notwithstanding the enormous outlay they have involved ; and that, therefore, a thorough reform of our existing sani- tary system is urgently required. — " On Infant Mortality in Manchester" : acomparison of the infant mortality in this city with that of several large towns as given in the Registrar General's returns. In this paper he states, " it is therefore clear from these returns that the stigma of carelessness with regard to their children, cast upon the mothers of the working class of Manchester, is most undeserved, and that, in fact, infants and young children are better cared for and attended to in Manchester than in any of the leading manufacturing towns in England." " On the Mortality Returns for Scotland for the last ten years." Session iSjo-ji. — " Observations of the Aurora of Oct. 25th, 1870"; "Observation of the Eclipse of the Sun, December, 1870 " ; " Remarks on Mr. Spence's Experiments on the Effects of Cold on the Strength of Cast Iron." About this time an interesting discussion took place in the Society on the effect of cold on cast iron, in which Dr. Joule, Mr. Brockbank, Dr. Hopkinson, and others took part. From some experiments, Mr. Spence concluded that a specimen of cast iron, having at 70° Fahr. a given power of resistance to transverse strain, will, on its temperature being reduced to zero, have that power increased by 3 per cent. Treating the numerical results of the experiments in accordance with the theory of errors, Mr. Baxendell comes to the conclusion that the experiments, though made with great care, offer no certain evidence that any sensible change takes place in the strength of cast iron when its temperature is reduced from D so Dr. Bottomley on the late jo' to zero Fahr. — " On a diurnal inequality in the direction and velocity of the wind apparently connected with the daily changes of Magnetic declination." Having combined the results of the anemograph observations made at Oxford during \%6j-6Z with those of the previous eight years, he finds a confirmation of the opinion expressed in a former paper, relative to a connection of wind movement and daily change of magnetic declination. He also examines whether the mean direction of the wind at Oxford in different years had any relation to the number of spots observed on the sun's disc. Taking the period from 1859 to 1868, it appears that the greatest angle of direction occurred in i860, which^ was a year of maximum solar spot frequency, and the least in 1866, when solar spots were least numerous. Session 18 j 1-^2. — "Note on the Destruction of St. Mary's Church, Crumpsall, on the 4th January, 1872, by fire from a lightning discharge " ; " On the Changes in the Distribu- tion of Barometric Pressure, Temperature, and Rainfall during a Solar Spot Period." Dividing a period of 1 1 years, from 1858 to 1868 inclusive, into two periods of maximum and minimum solar frequency, he finds the mean pressure under different winds, and the differences ; the differences under north-east, east, south-east, south-west, and west are too considerable to be fairly attributable to accidental causes. A comparison was then made of the mean pressure under north-east, east, and south-east winds with those under south-west and west winds ; a maximum difference occurred in i860 when solar spot frequency was at a maximum, and a minimum difference in 1867 when solar spot frequency was also at a minimum, and the general course of the differences has a remarkable similarity to that of the numbers representing the variations of solar spot frequency. From a comparison of temperature with dif- ferent winds he finds that in the first period (1858-62) the maximum temperature occurs under winds from south- Joseph Baxendell, F.R.S. 51 west, and in the second period (1862-68) under winds from about south south-east. Comparing the mean temperature under south-west winds with that under south and south- east winds, from the differences he finds a maximum in i860 and a minimum in 1867 ; it is therefore evident that the distribution of temperature under different winds like that of barometric pressure, is very sensibly influenced by changes which take place in solar activity. He makes a comparison of rainfall during the two periods, 1858-62 and 1862-68, under different winds; he finds that the amounts of rainfall under south-west and west winds are invariably greater than those under south-east and south winds during the years when the number of solar spots was above the average, and invariably less in the years when the number of solar spots was below the average, and further, that the greatest difference in the first series of years occurred in i860, at the time of a solar spot maximum, and that in the second series, in 1866, at or very near to the time of a solar spot minimum. — " On Distribution of Rainfall under different winds at St. Petersburg during a solar spot period." He states that the hypothesis which led to this investigation requires that great diversity should exist in the relative amounts of rainfall under different winds at different stations, but whatever may be the nature of the distribution at any station, the changes to which it will be subject will take place in a period identical with the solar spot period. After examining the tables of rainfall at St. Petersburg during the eleven years, 1854-64, he finds that the close agreement which exists at St. Petersburg between the maximum and minimum period of solar spots, and those of variation in the distribution of rainfall under different winds, gives increased value to the results derived from the Oxford observations, and affords additional sup- port to the hypothesis which he had advanced in a former paper, that changes in solar activity, and consequently in 52 Dr. Bottomley on the late the magnetic condition of the earth, produced corresponding changes in the direction and velocities of the great currents of the atmosphere, and in the distribution of barometric pressure, temperature, and rainfall. — " Notes on the Relative Velocities of different Winds at Southport and Eccles, near Manchester." Sessio7z i8y2-yj. — He made no communication to the Society. Session iS'/j-'/^.. — No communication. Session iSy^-yS. — "On a Source of atmospheric Ozone." In this paper he pre<^ents himself to our notice in a new phase not only as an observer, but as an experimenter. He had remarked that when fog or haze were prevalent it rarely happened that even the faintest trace of ozone could be obtained, and came to the conclusion that atmospheric ozone was absorbed or decomposed by haze or fog, and was given off or produced when evaporation changed haze or fog into visible vapour. He had also noticed that haze does not only prevent the coloration of the test papers, but it also rapidly bleaches those which already had been coloured by tho action of ozone. The bleaching effect is not produced if the papers are thoroughly wetted by immersion in water, and it has been attributed to another form of oxygen named antozene. The analogy of the constitution of visible vapour and spray from a breaking wave or a fountain led him to make some experiments in the vicinity of the fine fountains at the Arnfield and Hollingworth reservoirs in the Man- chester Corporation Waterworks district. At each locality boxes containing ozone papers were placed on the windward and on the leeward side of the fountains. The experiments at both localities showed a marked excess of ozone on the leeward side. The experiments, he thinks, prove that the spray from a fountain on evaporating gives off, or produces, atmospheric ozone and in this respect is similar to ordinary fog or haze. He advances the hypothesis that water exposed Jo Sep J I Baxendell^ F.R.S. 53 to the air has the power of condensing oxygen upon its surface into a thin film of ozone ; when, therefore, complete evaporation of the vesicles or globules of moisture which constitute a cloud or fog takes place, the ozone is left free to diffuse itself through the air, but when evaporation takes place from the surface of a large and practically inexhaustible mass of water the ozone is not set free, but remains adhering to the surface. To meet the objection that if ozone is formed in this way, test papers ought to be coloured very rapidly in a fog or dense haze, and that no bleaching action could take place upon papers already ozonised, he ventures to offer as an explanation, that ozone associated with moisture and in the presence of the oxidised potassiums, will combine with the freed iodine and form iodic acid, which, uniting with the potash, will form the colourless iodate of potash ; or it may be that the direct action of ozone on iodide of potassium is retarded, or altogether prevented, by an excess of moisture when the ozone is present in only small quanti- ties, as is usually the case in the atmosphere. That ozone should oxidise the free iodine as Mr. Baxendell suggests to iodic acid seems improbable. The following explanation seems possible: if ozone decompose iodide of potassium into iodine and free alkali, should the paper become slightly damp, the reverse action would take place, and the iodine would be converted into iodide and iodate of potassium. A member of this Society, to whom Mr. Baxendell had often mentioned the bleaching of the papers, stated that he thought he could distinguish those which had been bleached from those which had not been exposed. As a challenge Mr. Baxendell sent four numbered papers which were quite similar in appearance, but revealed a difference when tested ; two were stated to have been exposed, and two to be fresh papers. Mr. Baxendell wrote in reply that they were rightly grouped. The method of discrimination was extremely simple, and 54 DR- Bottomley on the late was communicated to him in the hope that it might be of service in his future work on ozone ; on dipping the papers into dilute hydrochloric acid, those which had been ozonised and bleached re-assumed a violet tint ; those which had not been exposed were initially unaffected. — "On the connec- tion of the Humidity of the Air and the amount of Ozone." Session i8y6-yy. — "On the Protection of Buildings from Lightning " ; remarks on Professor Maxwell's paper on the subject, read at the recent meeting of the British Association. — "On Changes in the Rates of Mortality from Different Diseases during the Twenty Years 1854-73," — a discussion of the Registrar General's mortality returns during the period, which he divides into two equal parts, comparing the death rates of eight of the principal infectious diseases ; the results show that the mortality from seven has diminished very sensibly, while that from small-pox shows an extra- ordinary increase, the percentage of increase of death rate being 86-3 ; he also found that the adult portion of the population were much more susceptible to its attacks. A comparison of diseases of the non-preventible class during the two periods showed for some an increase, and for others a decrease. He also gives an analysis of the death returns of a few of the more important diseases in the lists. From his results he concludes that sanitary measures, tested by their effect on the diseases which are universally admitted to be infectious, have produced a slight improvement in the public health which is equivalent to the saving of one life in every 134, or a reduction of 0'I7 in the general death rate ; but tested by their effect on the whole class of zymotic diseases they have caused no improvement what- ever, and have not even prevented an increase in the mortality from these diseases, which is equivalent to an extra loss of life in every 417. From the returns with regard to small-pox, he states that the experience of the last and of the present epidemic has furnished abundant Joseph Baxendett^ F.R.S. 55 proof that vaccination does not, as it did in Jenner's time and for many years after, afford an almost certain protection against its attacks. He also states that the reduction in the rate of mortality from the class of infectious or pre- ventible diseases, has been more than counterbalanced by an increase in the rate from the non-preventible class. This paper of Mr. Baxendell's did not pass without criticism. Another of our members, Dr. Arthur Ransome, replied to it in a paper printed in the sixth volume of the Memoirs (third series) entitled "Losses and Gains in the Death-toll of England and Wales during the last Thirty Years." Speaking of the source from which Mr. Baxendell drew the materials for his deductions, he states that unfor- tunately the returns of the Registrar General cannot be relied on for the species of information which he seeks to obtain from them ; the drawbacks to the utilityof the returns had often been pointed out, and in the early reports of the Registrar General, Dr. Farr himself complained of the imper- fect nomenclature of disease. In reference to Mr, Baxendell's remarks on the great increase of small-pox. Dr. Ransome states, "his remarks on this point are undoubtedly very important, and will need to be well weighed by those who are responsible for the effective performance of vaccination. It points to some imperfection in the operation, or to a possible deterioration in the quality of the lymph owing to its transmission too constantly through the human subject; in any case its cause is worthy of full and patient investiga- tion." With reference to sanitary improvements he states, "it will be seen that I entirely agree with Mr. Baxendell in thinking that the present sanitary system is very defective, but it by no means follows that it has done no good." Mr. Baxendell continued his investigations on the action of vaccination. His next paper was "On the Increased Mor- tality from Small-Pox." In this paper he continues his argument against vaccination as a preventive of small- 56 Dr. Bottomley on the late pox. As a test of its value he has taken the small-pox statistics of London — the best vaccinated town in the country — and compared the results of the five years 1849-52, before vaccination was made compulsory, with those of the five years 1869-73, when compulsory vaccination had been twenty years in operation ; the results confirm him in his previous opinion that vaccination had ceased to be a remedy. He states, "so far from vaccination having been the means of saving many thousand lives annually, as has often been very rashly stated, the stern facts recorded in the annual reports of the Registrar General prove beyond all question that, in the best vaccinated city in the kingdom, the death rate among the vaccinated alone is now equal to that which prevailed among the unvaccinated before com- pulsory vaccination laws were passed ; that the number of cases from small-pox has nearly doubled, and that the number of deaths of adults has also greatly increased." Session i8yy-y8. — "Transit of the Shadow of Titan across the Disc of Saturn, November 23rd, 1877." Session iSyS-yg. — " Observations of Dr. Klein's new Lunar Crater near Hyginus, made at the Observatory, Birk- dale"; "On the Meteorological Effects of the position of the Moon with respect to the Sun." From observations made at Southport, he concludes that at Southport, during the winter months, the mean daily range of temperature is on the average greater on the days of full moon than on the days of new moon. From cloud observations, he finds that at 9 a.m., the mean amount of cloud is slightly greater on days of new moon than on days of full moon ; at I p.m. the amounts are nearly equal ; but at 9 p.m. the amount on days of full moon is greater than on days of new moon. It has been supposed by some meteorologists that the full moon had the effect of partially dispersing the clouds, but his own results show very clearly that any effect which the moon may have is of an opposite character, as in every winter Joseph Baxendelly F.R.S. 57 the mean amount of cloud was greater at the time of full moon than of new moon. The observations of mean daily temperature show that the days of full moon were on the average ri9° colder than the days of new moon. He was led to infer that at times of full moon, northerly winds had been more frequent than at the times of new moon ; the observations made at Southport confirmed this view. The numbers obtained also indicated that the frequency of northerly winds under the full moon and last quarter, as compared with that under the new moon and first quarter, has gradually diminished during the seven years (1871-78) of observation. Assuming that the diminution is due to the gradual diminution of solar activity, the ratio might be expected to be a minimum during the year 1878-79. An examination of the Radcliffe observations confirmed his opinion that the moon exercises a noticeable influence on the direction of the wind. Session i8yg-i88o. — " Results of Observations of the Double Period Variable Star R Sagittae " ; " Note on three New Stars " ; " Results of Observations of the Variable Star T Aquilae." Session 1880-81. — "Ozone and the Rate of Mortality of Southport during the nine years 1872- 1880." From observations made during the period, he found that in four of the five years of low amounts of ozone the zymotic death rate was above the mean, and in the fifth slightly below ; and in the four years of high amounts, the rate was always below the average. During the five years of low amounts of ozone the gross death rate was 12*8 per cent greater than in the four years of high amounts of ozone, the local death rate I0"9 per cent, and the zymotic death rate 92*6 per cent greater. He thinks that the corrected amounts of ozone represent the actual purity of the air at Southport during the nine years, and that variations in the actual amount exercise a very sensible influence upon the state of public health. 58 Joseph Baxendell, F.R.S. Session 1881-82. — " Note on the Variable Stars U Can is minoris, V Geminorum, and U Bootis." During the next two sessions he made no communications. Session 1884.-8^. — " Notes on the visibility of the Moon during total Lunar Eclipses," His last paper was " On the Reversion of the Minima of the double period Variable Star R Sagittae," read November i8th, 1884. Mr. Baxendell sought no applause while living ; to refrain from adding it now will be to respect a wish, casually expressed about three years ago, that when his time came he should like to slip out of the world as quietly as possible. The approval of his work, by those who are capable of judging of its merits, will supply a testimony to its worth of greater value than any studied eulogy with which the writer of this memoir could conclude his task. Proceedings. 59 Ordinary Meeting, December 27th, 1887. Mr. W. H. Johnson in the Chair. Reference was made to the untimely loss sustained by the Society in the sudden death of its President, the late Prof. Balfour Stewart. It was thought more suitable to postpone passing a vote of condolence to the late President's family in consequence of the attendance being very small. Mr. James Smith communicated the following note on the bi-centenary of the Principia : — This year being the bi-centenary of the publication ot Newton's Principia^ I think the fact should be noted in our Memoirs, as it ought not to be allowed to pass over without attention being directed to it. The second edition of the Principia was published in 171 3, and is known as "Cotes' Edition," he having assisted Newton in the revision of the work, and written a preface to it. Newton had a very high opinion of his mathematical abilities. The third edition, and the last published during the life-time of the great author, is dated 1726, and is known as " Pemberton's Edition," he having had charge of revising it under the direction of Newton. It was the intention of Dr. Pemberton to have published an English translation of the Principia, with a comment, but the publication of Motte's translation in 1729, prevented him from proceeding with his design. Very little appears to be known about Andrew Motte, whose name is thus associated with the Principia, and who deserves much praise for his labours in connection with it. 6o Proceedings. Ordinary Meeting, January loth, 1888. Professor W. C. WILLIAMSON, LL.D., F.R.S., Vice-President, in the Chair. The Chairman referred to the sudden death of the President of the Society, Professor Balfour Stewart, LL.D., F.R.S., and it was moved by Dr. Burghardt, seconded by Mr. Francis Jones, and resolved, — " That the members of the Manchester Literary and Philosophical Society desire respectfully to offer their sincere sympathy and condolence to Mrs. Stewart and her family in the sad bereavement they have sustained in the loss of Dr. Stewart, the esteemed and distinguished President of the Society ; and that the Secretaries be requested to communicate the resolution to Mrs. Stewart." The Chairman stated that a similar resolution had been adopted by the Council of the Society, and that the Council had requested Dr. Schuster to prepare a memoir on the life and work of Dr. Stewart, to be read before the Society. Mr. Faraday communicated the substance of a letter from Mr. George J. Romanes, M.A., LL.D., F.R.S., with reference to experiments bearing on the theory of physio- logical selection. The letter suggested that "splitting" botanists should look out for constant varieties, sow the seeds together with some standard plants for subsequent comparison with the progeny, and then either send all the material to the writer (with diagnostic descriptions of the points of difference), or, if they preferred to conduct the experiments on hybridisation for themselves, should com- municate with Mr. Romanes as to the method. Professor WILLIAMSON announced that the gigantic fossil stigmarian roots of a lepidodendroid or sigillarian tree, discovered some time since, had been erected in the Museum of the Owens College, forming the noblest example of fossilised vegetable life yet discovered. spherical Wave of Light. 6i An application of Huyghens' Principle to a spherical wave of light. By R. F. Gwyther, M.A. This is an attempt to form a theory of diffraction on geometrical principles only. To make such an attempt does not appear to me unreasonable, since, with our present knowledge, one might prefer to look upon the breaking up of a wave as a geometrical artifice rather than as a geometrical representation of some physical phenomena. Introduction. We can easily express in terms of co-ordinates the dis- placements resolved along axes in a hypothetical spherical wave, and for our purposes we need not at first consider any difficulty there may be in understanding how such a wave could originate ; our equations will express the nature of its progress when once originated. As we consider light to consist of displacements, and to be propagated by strains in an ether in which the velocity of normal vibrations is incomparably greater than that of transverse vibrations, and as the principle of the independent co-existence of small motions is essential to the whole theory of light, it is no further hypothesis to assume that at any moment we may regard each element of a disturbed spherical surface to be itself an origin of an elemental wave the resultant of all such elemental waves reproducing for future time the actual wave motion which we were originally considering. It is my object to determine the form of the displacement in the secondary waves, in order that the resultant displacements may be everywhere equivalent to those of the original wave. In the first place, I show that if an elemental wave is to represent a plane polarised ray of which the displacement E 62 Mr. Gwyther on a is directed along the axis of/, in order that it may satisfy the condition of admitting of resolution, the displacements must take the form 'i=fx{cc.r)y l=-i^lx.r)yz. Making use of a form of solution of the equations of light given by the author in a previous paper quoted, I show that we may write these s^=-2-^^^;,niT^sin-(^/-r) + etc. 77 = S ^-^1 Sin— (6^ - r) + etc. ^=-S--^^sin-(^/-r) + etc. where a^ and b^ are any constants. Without proceeding further we may notice that this agrees in form with the solution found on dynamical grounds by Professor Stokes. We shall obtain his solution if we put ;^ = 2 or 3, ^2 = ^3 = ^2 = <^3=^, and accelerate the phase by - . Before going further it may be well to explain 4 that the difficulty I find about this form of displacement consists in this fact and its consequences. If we consider a point immediately in front of the point of origin of the secondary wave for which j = 0, s = 0, x=r we should have n = — sin ~ {bt - r), ' r A and if we consider the point for which ,r - 0, j = 0, ^ = r, we should have ^a . 27r , giving a displacement one-half of that immediately in front of the aperture. And if, instead of considering an element spherical Wave of Light. 6;^ of surface only, we integrate over a finite portion we get a corresponding result. Hence it would seem probable either that n is greater than 2 or that h = 0. Returning to the consideration of the problem, imaginino- disturbances of the form which I have found to originate from every portion of the spherical surface, and finding their resultant at some point, there appear in the expressions, (i) terms depending upon A/<: where c is the radius of the original sphere, which terms can not be made to disappear, and which express the expected fact that we can only apply the principle to a wave of which the radius is large compared with the wave length, and (2) terms depending upon X/r where r is the distance of the point considered from the sur- face of the sphere, which all disappear upon integration by a continual appearance of a set of similar series. As these terms disappear we obtain from this investigation no criterion of the value of n or of d, but the fact of their disappearance gives a strong confirmation (which appears in other ways in the paper) of the appropriate nature of the solution of the differential equation used, and of the possibility of satisfying the conditions without taking into consideration any wave of condensation. The only conditions which we thus obtain are i;(-i)X = 0. I A In the last part of the paper I consider the case of a wave converging to the origin. The wave being the secondary wave representing a plane polarised wave, reversed by the reversal of the velocity, I show that the resultant displacement and rotation at the origin will be of the same nature as the original displacement at the origin, if n have the values 2 and 3, and ^2 = 0. ^2 = ^3 = ^3 = -.- 2 A. 64 Mr. Gwyther on a I thus get as the final form of displacement in the secondary wave xyz . 27r 4 = T-sin— (/'/ - /') 2X. The object of this paper is to study to what extent an expression can be found to represent, on the basis of Huy- ghens' principle, the action of a plane polarised ray of light. From simple principles we may learn something of the way in which the co-ordinates must enter such an expression so that they may allow of resolution. Imagine a ray of plane polarised light to travel along the axis of x and let its components be <3:cosa and a^m.a along the axes of j/ and z, and let, if possible, the consequent disturbance at a point x.y.z be represented by a dis- turbance in the secondary wave, such that the part of it arising from the component ^cosa along the axis of j/ may be U = ^COSa(/i +/2J1/ +/3.S: ^-f^f- ■vfr.yz 4-/6^2 + &:c.) V = acosa((])i + (p^y + ^gS + cp^y- + cp^yz + (p^z'^ + &c.) W = ^cosa(-(//i + -ii^^y + ;//3S + -^^y"^ + -^^yz + \//6^^ + &c.) when all the functions contain x and r only {y" + z^ being always written r^ — x"^ whenever it appears) and the series being continued in the same way. Hence the part which arises from <^sina along the axis of z will be represented by U' = ^sina(/i +f,z -f^y ^W -f^yz ^fina = ^(4/1 + ;^2Y + ;P3Z -I- ;i4 Y^ + ;/.5YZ + i^gZ^ + &c.) where Y =J^'coso + isinct Z = ccosa — ji'sinct. Hence, as we include all the powers ofj^ + ^r^ and Y- + Z'' in the functional part, we may conclude that /l=/4=/5=/6=&C.=0. <^2 = 3 = 04 =" &C. = 0. -i/zs + 06 = 0. ^2 = ^3 = ^6 = &C. =0. \//4 + ^5 = 0. And therefore that the displacement will take the simpler form U = ^cosa { /a J +^? } \ V = «COSa{(/)i-;//4>'2 + 0632j I (j) W = ^COSa { ;//! + 4/4/ - 6J^'^} ) But this gives merely the form of disturbance suitable for resolution, and does not distinguish the forms for representing suitably the disturbance along the different axes. We may consider it obvious that ^i = 0 when the displacement is along the axis of y, the others will be con- sidered later, when we shall show that/3 = 0 1/^4 = 0. §2. I shall make use of the solution of the equations of the vibration of light given by me in a paper bearing that title (Proceedijigs of Camb. Phil. Society, vol. 5, page 279), and the suitableness of this solution will receive strong support in the course of the paper, from considerations arising from other circumstances than those detailed in that paper. 66 Mr. Gwyther on a The solution is in this form. If (S.^?.^) are the components of the displacement in a light wave from a point source where / stands for 27r/X, and u_x and ^^_i any two homo- geneous functions whatever of degree- i, from which the terms of other degrees are derived by the laws. ?/_"2 + ^V^Z'-l = 0, w_3 + rv^^'-2 = 0, &C.J and the condition -^ + ^ + — = 0, will be satisfied provided ax ay dz ^ x^v _i + y-yiV -I + s/u ^i = 0.J These expressions are to be used in this paper in their full form without approximation, and I shall first show the forms which the terms of other orders will take when where ?/„ is homogeneous of the 72"* order in x.y.z. By continually using the formula 2_ r"" y ^V ^ra— ^m-\ " ^"*+l 7^.2 = yU^I V *?/„ (« - I );^ V '^Un (^^ - I )n{ii-\- i)(/? + 2)?^^ + 2 .»+i ^"+3 V ^/A, (;g-2)(;^-i)vX {n-2){n- \)n{n^ i)vX (^^j^2)^^^(^«jf3K ■^ ^"+3 The general term in the expansion being of the form ^n-3+1 - ^ ^."-34-3 + ^'^^• + ( + y ./; -1-74-1 spherical Wave of Light. 6y from which it appears that the last term of the expansion will be that for which q = n. As an example we may take a case of vibration along the parallels of a system of spheres referred to a pole on the axis of x. n= ^sin;^(^/-r)-^3C0S/(^/-r) ' ^ - - ^sin/(^/ - r) ■^j^,f.o^p{bt - r) in which the vibrations are accurately on the spheres. And if we perform the expansion for a case of vibrations which are to a first approximation along the corresponding meri- dians, we get »= - {f -j|^}=in/(^'-'-)+|^cos/(*/-'-) In accordance with this solution and the previously considered form for the displacement in a secondary wave, representing, on Huyghens' principle, an elementary por- tion of a plane polarised wave, we must have in the assumed form of such a secondary disturbance. 2?^-i = - ^,.+1 r ru-i = 2- ^,,^1 •(2) r" We have now, if possible, to find the values and relations between the constants in this expression, and to limit the values of n. j\rote.—lt is impossible to treat the diffraction question without reference to Professor Stokes' work on the subject. 6S Mr. Gwyther ou a and to show the relation to the nature of his solution and the differences from it, I will compare equation (39) page 27 of his reprinted papers (with his notation). ■'%-;;^/('-3*iSi/('-;)-S^A<'-'''- each term of which he explains on page 279. Write /(/) = <:sin27r(^//X, replace Lm.n by xir.ylr.z\r, com- plete the integration and separate into two parts, we then get Kt x(l'x + 7n'y^n'z)\ .277.. . f^xjl'x 4- my + n'z) /'\ + (^ y, • - ^3j (xil'x + 7ny + n'z) . 2Trb, ^ . ^i' — v^ — -^'"^('''-'■> (T^xil'x + 7ny + n'z) t \ V (\ra 2Trb , . f ^(^\' . 27r^, , --|1 / .-. , the wave length in the two waves being in the ratio d/a. Each of these expansions separately is of the form that I have used, the first being without condensation, the second without rotation. If we now make a = ^, the second expansion gives a single term only, representing a wave of infinite wave length, which would be sensible only near the point of origin of the wave, 7V-cr .• — r /' 3^^^'^r + m'y 4- ;/.)! / ^ Y.in'"^^^ / ^TzDb ax d (l'x + m'y + n'z^ / X V • ^tt/^/ / ^ .„ SpJierical Wave of Light. 69 and as far as this term is concerned d't, dn d'C ^ T- + y + V = 0- dx dy dz d^ /27r^V. ''t, (27rb\\ and a^-r naust be written , • as explained in Article 9 of Professor Stokes' paper. If we had considered the full form of the equation on the elastic solid principle, we should have been led to add to £.)].? terms -^, — , -~ where d> has the form ax ay dz ^ a . 2Trbt I'x + my + n'z . zizbf -sin—— + ^ sin^— ^ f(P + ^ + r) _ :,(px' + £y- + rr + /lyz +jzx + Lxy)} ^-^^M _^ ^^^ (or rather such part of it as has the form yf(x,r), the terms being final terms in the form of expansion, which I have used throughout. I 3- I have as yet spoken of a plane polarised wave of light, but obviously any expression which can, on Huyghens' principle, represent a secondary wave corresponding to an element of a plane wave, can equally well represent the secondary wave corresponding to an element of any wave front whatever, provided only the radii of curvature at the element considered are large compared with the wave length. I shall accordingly attempt to find the conditions that we must have in order that a disturbance in a spherical wave of radius c (where X/<: is an infinitesimal quantity), may be reconstructed by the integral disturbances of certain secondary waves arising from all points upon its surface. yo Mr. Gwyther on a Consider, first, the disturbance generally, represented by ;;2(;;^ + i)rw + 2)^ + 3):^"'^ 7;z(w — i):r'"~^2; (;;/ + \){m + 2)^'"2' V8/lsin/(^/-r) - i):r'"-^2; (;;/ + i)(;;2 + 2)^'"^ , /, v „ TM^i ^ %. ^ |/2/.cos^(/;/-r) + &c. with a similar expression for ^, in accordance with (2) which represents a displacement along parallels of spheres having the axis of x for pole. The resultant displacement represented by the leading term is — '"—^ri — > the constant which we may call the stre7igth of the pole being taken as units to avoid constant repetition of it. Let us imagine that on a sphere of radius c this dis- placement is broken up and replaced by a series of secondary waves in the usual manner. Let P be the point at which we are going to consider the integral displacement, and let the distance of P from the origin be written p, and let the direction cosines of the radius of P and the tangents to the meridians and parallel through P of a concentric sphere be given by the scheme. cosa . sina cos/3 . sinasin/3 sina . - cosocos/3 . - cosa sin/3 0 . sin/3 . - cos/3 and let these lines be considered as a new set of axes. Let OP meet the surface of the sphere of radius c \\\ P>, and let the pole of the meridians and parallels be A. Let O be any point on the sphere, <:cos0, rsinOcossinysina ^^^ cos'-ysinycosg ,g3p,,ti,.g, c c and applying to each of these the formulae (i) obtained as the necessary form of displacement in the secondary wave, and writing x and y for X and Y, we get ^1 = cos'"ysinysinc^(.T./')y - cos'"ysinycosc/^(jv:.r)_y 7?i = cos'"ysinysin30i(^.r) 4i = cos"*ysinycosc|0i(.T.r) + <^ii{x.r)y^^ + cos"'7sinysinc^4(^.?')j^- ; all being divided by c. We must now resolve these parallel to the axes, and get t, = ticos0 + 7/isin0 ; r] = ^isin0cos0 — t;iCos9cos0 - Cisin0 ; ^ = ^isin0sin0 - rjiCOsOsincj) + 4icos0. 72 Mr. Gwyther 07t a And each of these is to be affected by c-s'mddddij) and integrated between the Hmits of 0 and 27r for (p and 0 and TT for a The integration with regard to <^ is easily done, and we get ^ depends onyg only >/ depends ony^ and \pi, and ^ is the subject of our further investigations. Resolving again parallel to the original axes we see that to reproduce the original displacement at P we must have hence we conclude ^3 = 0, ^^ = 0, and thus have further simplified the formulae (i). Then ^= I / (cosacosO + sinasinf^cos^)'Vsin9^0^(^ O o X { [/2(x.r)ysmd - (pi{x.r)cosd)s'masm-({) + (^(pi{x.r) + (f)6{x.r)y"^(^cosasmd - sinacos0cos(^)cos(/)}. The integration with regard to (p can be completed thus / (cosacos0 + sinasin0cos0)'"sinasin"0^0 {Uliffl I ^ I cos"'acos"*0sina + ~-^ -^cos'"~"acos"'~-0sin^asin-O + etc. \ 2.4 J Let us separate in this the parts containing cos"'asina cos"'~2asina, etc., and at the same time change the integral from one with regard to 0 to one with regard to r, by writing ;r + ^=fjcos6. y = psinO We thus get as the coefficient of 7rcos'"asina/p"'+^ spherical Wave of LigJit. 73 +/[/2(-'--'-)(« + 4'" + "'^"'^ ^\{^.r){x + c)'"-^ - K(x.r){x + ^)™+'} The limits between which the integrals are to be taken correspond to the values 0 and w of 0, and depend upon whether the point is within or without the sphere. The expression for f^^x-r^y is to be the expansion beginning 2^,,^"->sin/{^(T + /) - r- r + i]lr"-^^, that for f^ipcr^v" is to be selected out of that beginning 2/^,X~Tsin/{/^(T + /) - c-r^-i)\r"^^, and that for 0i(x.r) is made up of that part of the preceding which does not contain j, and the expansion beginning 2^,.^"sin/{^(T ^t)-c-r^ /}/r"+\ where T stands for the time at which the displacement reached the surface of the sphere of radius c and t the further time before the secondary wave reaches Q. 2 denotes summation for different values of ii and will be generally omitted, and s and c will be written for We expand these by the method previously explained so as to get solutions of the differential equations, these solutions will also satisfy the condition of no condensation if r„= -a,,. Substitute these expressions in the argument of our integral, and write 74 Mr. Gwyther oji a 2/2 = the expression we should obtain by writing {71 - i){?i - 2%,x''-^ for c,,x''-^ (n.[ii - i)a,^ + 2b^x"~^ for a^x"" {n - 2){fi - -^b^x"--^ for b,,x]''-'^ 21^ = the expression we should obtain by writing {n - I )- - -{71 - d,)c^x'^-'^ for r„aj"- ^ {7t..-{7i- 3)«„ + d,{n -2){n- 3)^„]*'"-^ for a,{f]' {n - 2)- --in - s)b„x"'-^ for b,^x"--^, and so on. Then our integral will take the form where TI -^ ?/2 71(71 +l)Uo 2r »i+i U^ {fl - \)7m-}»{|-/!"4] and u^ = -3 Vo dr ^ ^?'- dr In differentiating with regard to r, we must bear in mind that dx _ r dy _ r{x + c) ■Jk c dr cy spherical Wave of Light. 75 On differentiating, for example, — ^ let us write the result -——, ~, and let us write the subsequent numerators re- cr ^"+1' suiting from successive differentiation Uo, 21"' etc. Also let us write u = w + vy- -\-ty^ + sy^' + ?y^ + etc. and differentiate/ times, using Leibnitz' Theorem. ziP={- iY{i^' - 2pv^~\x + c) -p{p - i)z:^'-' + 4/(/ - i)/^-> + cf + AP{P- i)(/ - 2y-\x + c) +p-(p - 3)F-' - Sp--{p - 2)sP-%x + cf - 12P- -(p - s)s^-\x + cy - 6p-{p - 4)s^-\x + c) -p- - -{p - 5)s^-' + etc. } in which j/ is put zero. We are now in a position to do the formal integration, as a first step we have the formulae ^1 r" 7h ^0 cr""- ^ 2r ■n+l -1 _ u^' 1 ^''~ -2){n- 2cr" i)tij - 2^2' ^3 c^r''- -2 1 2cr''- -2 (n - 2) — (7i+i)Uo (u - 2){n — 1)1^2 t/i 2^V-^ 2rr"-^ (n-^y-mio' _ {n - 3)(?i - 2)212 uj (;/-3)---(;g + 2)?/, _ (;/-3)---;/?^2 (;^ - 3)(^^ - 2)2^4 u^ 48^'*+^ i6r"+^ 16/-"-^ 48r"-5 In calculating this expression the same kind of series continually presents itself. We may write this series in the general form n{7i+ iy--{n + f- i) -p{n + s){;i + s + i)-—{7i + s + t- 1) ^PiP '(^f^ + 2s)(n + 2^ + i)- - -(;/ + 2S + / - i) - etc. Writing n(7i -f i) — {71 + f- i) = ?/,(, and E for i + A ye> Mr. Gwyther on a the series becomes y ^ 1.2 J = (i-EOX. = (i + E + E^ + &c. + E^-i)^( - t^Yu,,, and the series is seen to be zero \i p>ty and \i p = t the value of the series is (^ — s)\t\ Similarly the series n{ri - k)- - -(ti - (/ - i)^) -/(// + k)n{n - k)- - -(;^ - (/ - 2)k) + etc. = (i + E + E^ + &c. + E^--i)^X - ^ )X = Oif/>/. = (- i)7! k"', \ip = t. I shall write down the results of the simplifications, in which I have merely treated y as zero and x^-=^f% but not taken the other steps towards finding the values at the limits. 7/2 -= 2(«^,. + r„ - ^,>"-^(^ + ^)'"^ + ^ + ^n^"(^^' + ^)"A^" ~ ' v'=^ - 2{n.{n - i)a, + 2(n - i)c^~ 2(;2 - 2)/4}^"-%r + ^^''-1 - {m + i){m + 2){2na^ + c,, - T,b,)x"-\x + cY" - {m + i)(;// + 2)((;/ - i)^, - 2^,>"-=^(^ + cY'lcr^'~\ In this it will be noticed that (i) (;r+^)"'+^ is the highest power of (;ir+<:) which appears; (2) that c appears to the de- nominator of every one of these expressions except that for vi ; (3) that the power of r to the denominator is always lower than that of ,r in the numerator, and that thus any expression such as -;p can be written ~^(^x + c-c) or ^^^pcosd-c). Before we consider the consequences of substituting the values at the limits, we may notice that, as we are taking into account terms which must be neglected unless we profess a minute accuracy, we must not neglect the terms which will arise from other terms than the leading term in the expression for the original wave which was broken up. spherical Wave of Light. jj Referring to (3) we see that we are considering 4 = 0 ^={,:^2--^ 8/V-+^ ^^^— + etc.}sin/(/;/-r) {(j?i^i)(7n + 2)x"'z 1 - y ,^V-+^ etc.|cos/(^/- .) Writing V1.U2.V3, etc., for the coefficients which we get when we take these into account, we get Vi = - 2a^x'\x + cf'+'^jr". U2 = 2{?ian + Cn - d„)x"-'^{x + c)"'^'^lcr" - {m + i)(;// + 2)a,,x"-\x + cy"'/r'"~^ etc. Where we see that in such coefficient we get a part independent of r, and that the coefficients of such terms in order differ only from the coefficients in the corresponding terms of the original expansion by a constant factor. It will be noticed that these coefficients are obtained by integration over the sphere merely, and are quite indepen- dent of the special form of expansion which I have used in the secondary wave. The use of that special form of expansion has been to cause the disappearance of all terms from the integral which might have appeared affected by A/r, and which would have been suitable only in the immediate neighbourhood of the sphere of radius c. We might, in fact, take any constant coefficients in an expansion of the same form, and forming the conditions for the dis- appearance of the terms in X/r, etc., infer from their linear character that the form of expansion must be that which I have used. Also as we shall see later the coefficients independent of c in V1.U2, etc., can be inferred from the first term of the expanded expression for the original displacement, thus giving additional evidence of the propriety of the form of expansion used. Proceeding now to the consideration of the actual value of the integral displacement, — if we consider first a point F 78 Mr. Gwyther on a outside the sphere then p > approaches the value X. spherical Wave of Light. yg The solution is still left indefinite ; to make it definite in the last part of this paper I shall consider values of g<\. It is needless to consider the general case of dis- placement of a sphere, it offers no further difficulties and gives no further conditions. If we had, in what precedes, integrated only over that part of the spherical surface which presents itself to P (a case which in the limit corresponds to the integration over an infinite plane), we should have obtained in addition to the principal terms already treated, terms arising from the boundary of which the only part sensible would be — cos/{^(T + /) - c-y + /}, which corresponds to the value 2 of n, and in which y stands for the length of the tangent from the point to the sphere. This term is of the same order of quantities as the terms which we have called principal terms. In the last part of this paper I attempt to show that b^ = 0. Note. — It might be objected that the displacement, but not the velocity of displacement has been here considered. But our expressions will give the requisite velocity of dis- placement, as may be easily proved. It must be remembered that we are attempting to satisfy the conditions of motion by expressions into which the time enters only in the form ^4* The relation between the displacement and rotation at any point of a spherical wave are such that if V and W are the coefficients in the components of the displacement along the tangents to the meridian and parallel at the point, then /W/2 and — />V/2 are the corresponding coefficients in the components of the rotation, the trigonometrical terms having been omitted for brevity. Continuing to omit the trigonometrical terms, let us form the expression for the secondary wave from the dis- placement, and then form the expression for the rotation in the secondary wave. Thus we get 2Y IP = - Y(b^ - a,)x-'yz + Wx'''-'{a„{x'^ + s^) + b,f^ 2Zlp = - N{pe'-^{aSx'-' +ji/^) + h,z'- + W(/;, - a,)x''-^yz all divided by r'^+2. It is more convenient to write these 2X// - - W(^,_i - b,,_^ + b,,^-^x''-^y + etc. 2Y// = W{(«,_i - A,_i + ^«+i)^" + K_i - /^„_i):r«- V}etc. zZlp = - W(^„_i - b„_-^x""-yz - etc. spherical Wave of LigJit. 8i all divided by r^+\ where I have omitted the terms relating to V which are identical in form with those retained. We may now argue that if for any reason the values of 7t and of the coefficients a,^ and b,^ are determinate in the expressions for the displacement, we shall have the same determinancy about the coefficients in the expressions for the rotation which is a vector of identical form. Or we may form the expressions for the secondary wave representing the original rotation, which ought to agree with that just written not only when the integration is performed over the whole surface of the sphere, but if extended over any portion of it. By either line of reasoning we should conclude that \i p be the least value of ii, we get and finally Or fp+1 0, or 2(-i)X = 0. From this we conclude that if 2 is the least value of n h = 0, as we have said before it is reasonable to expect, and of which a proof will be offered in the next section. § 5. We have as yet considered a solution of the fundamental differential equation which proceeds by powers of X/r and is convergent if ?^>X, but which is not only infinite when ;'=0, but is also still a function of the direction of the vanishing vector. It is, however, evident that there is also a solution in ascending powers of r/X, which will not be a terminating series : these two series must give us no dis- continuity when r=\. 82 Mr. Gwyther on a Instead of trying to satisfy this condition, let us imagine that a displacement directed along the axis of 7, and propa- gated along that of x^ is broken up at the origin, and geometrically represented at a distance from the origin by a secondary spherical wave of the form which has been considered in this paper. Let us imagine also that this secondary wave has travelled till its displacements lie on a sphere of radius r which is large compared with X, so that the first terms are the only terms which are sensible, and then imagine the velocities reversed, so that, since the forces acting in the medium depend upon displacements and not on velocities, the wave will reverse its course tracing out its previous history in reversed order, and let us examine the nature of the resulting motion at the origin. In general terms we know that we shall obtain a wave converging to the origin and then diverging outwards again. Our notation being the same as before, imagine the sphere of radius c to be drawn, and that the displacements upon it at a point {x.y.z) are given by each affected by sin/|/|/^(T + /, 4- /) - ^+ r + j|/^^+\ where I have written the first term only of the expansion and k has the same ranee of values as n and aj, = K^, b^, = ^k' 84 Mr. Gwyther on a These displacements must now be resolved along a set of fixed axes, most conveniently that set of which the axis of X passes through P, thus 4 = ^iCOsQ + >7isin0 1^2 = ^isin0cos0 - ^icos0cos(^ + <^isin^ <^2 = sisin0sin^ - 7/iCos6sin(/) - - / / ^U_isin0sin iirKpdOdcp = + — (A2 + B2)cosacos/3 / I rXJ -i^inOcosdsirKpdddcp + I I ^U _ismdcos(l)ded(j) spherical Wave of Light. 85 = -^(A2+B2)sin/3. o It is obvious that this represents a displacement of the same nature as the original displacement, namely along the original axis of j. When ?2 =^ 3 we get no component. When ;2 = 4 the displacement at the origin assumes a different direction, and we are therefore led to consider the admissible values of ;/ to be 2 and 3. To determine the nature further — the original displace- ment being sin/(^T— .t-) directed along the axis of jj/, the rotation is given by — -cos/(<^T— ,t'). And if we form the expression for the rotation in the secondary wave, and then find the integral rotation at the origin, it should be related to the original rotation as the integral displacement at the origin is to the original displacement. The expres- sions for the rotation in the secondary waves are : 2X1 = 0. 2Y1 =/2^U_iros/|/;(T + 2Q + ^|/\^" 2Z1 = -/2:-,U_iCos/-j /;(T + 2/,) + J -A^". We must resolve these along the fixed axes as before, and integrate over the whole sphere. Thus X2 = YisinO Y2 = - Yicos0cos(^ + ZisirK^ Z2 = - Yicos0sin0 - ZiCOS(/). Pursuing the integration we now see that we get no com- ponent corresponding to ;^ = 2, and that when ^2 = 3 the resultant rotation will not have the suitable direction unless A3 =63. ^6 Mr. Gwyther on a We in that case have ^U_i = - A3^{sin/3cos^ + cosacos/3sin^} wU_i -• Ag^Ksinasine + cosacos0cos^)cos/3 - sin/3cos0sin(^} = — /x\3sinasin/3cos;;/;(T - 24)/\. 2C / / Y-.'imddddfp -II ATT . -^A3Cosasin/3cos//;(T + 2^o)/X. Zosin = - — M3Cos/3cos/^(T + 24)/\. This integral rotation has the same direction as the original rotation : as far as concerns the actual magnitude, it is obvious from the outset that the displacement in the secondary wave will be of — 2 dimensions in space. With- out speculating upon the absolute relation between the original displacement at the origin, and the integral dis- placement here found, it seems reasonable to expect that the relationship between the original and integral displace- ment should be the same as that between original and integral rotation. This requires that Ag^ A2 + B2. Taking this in connection with the conditions previously obtained, viz. : n = 2 and 3. A2 = A,. A.^A3^^ we have as our final determination. B2 = 0. A, = A3=B3=;^. 2A spherical Wave of Light. 87 and the form of displacement in the secondary wave is found to be ^=-fsin^(^/-.)/.X. The resultant displacement being x(x + r) . 27r 88 Proceedings. MICROSCOPICAL AND NATURAL HISTORY SECTION. Ordinary Meeting, January i6th, 1888. Professor W. C. Williamson, F.R.S., President of the Section, in the Chair. Mr. W. Leach was elected an associate of the Section. Mr. H. Hyde exhibited the following uncommon plants : Cainelina sativa ; Neslia paniculata ; Saponaria vaccaria ; Silene dichotoma ; and Salvia verticillata ; all found on a refuse heap on the canal bank at BoUington, Cheshire, in 1886; also Lepidmm latifoliiun, found on the site of the new museum, South Kensington ; and Galinsogea parviflora, which grows abundantly about Kew. Mr. P. Cameron exhibited a new species of PJiyllotorna, from Norwich, which he proposes to name PJiyllotoina fitmipennisy Cameron. It comes nearest to the poplar leaf- miner Phyllotoma ochropoda, but is very distinct from it in the colour of the tegular, legs, and wings, and in the form of the head. Dr. Alex. Hodgkinson gave a communication on the effects of diamond cuts on glass. The President described some anomalous cellular structures developed within the vascular cellular tissues of some of the plants of the Coal measures. Mr. W. L. Torrance exhibited a series of photographs from Java. Proceedings. 89 PHYSICAL AND MATHEMATICAL SECTION. Ordinary Meeting, January i8th, 1888. Dr. BOTTOMLEY in the Chair. Dr. BOTTOMLEY stated that he wished to call attention to an error in his paper, " On the Composition of projections in geometry of two dimensions," published in Vol. X., 3rd series of the Society's Memoirs; on page 15, it is stated that the perimeter of the ellipse nf\x - of + /\vil{x - d)y + (4 - yn^))/"" = wV^ is equal to the perimeter of the circle {x-af-v^y-hf^c"^ from which it is derived — this, however, is not correct, the axes of the ellipse are ^(i +/) and ^(i — /), and the statement holds only in the case when /= 0, it will, however, be approxi- mately true if / be a very small quantity, using a method of approximation adopted in some mathematical tables. 90 Proceedings. Ordinary Meeting, January 24th, i! Mr. Charles Bailey, F.L.S., in the Chair. Dr. Bottomley read an additional note on " The equations expressing the decomposition of Potassic Chlorate by heat." He said : — In a previous note, published in the current volume of Proceedings and Memoirs^ the general equation was written as follows : — 2PKCIO3 = 2QKCIO4 + 2(P - Q)KC1 + (3P - 4Q)02. A more convenient form would, I think, be obtained by dividing both sides by 2, giving the following equation : — PKCIO3 = QKCIO4 + (P - Q)KC1 + ^^-^^^Oa. This form admits of a greater number of solutions with a given number of molecules of KCIO3 than the previous form. It also imposes a new condition on the values of P ; they must be even numbers. If P = 22, in addition to the equations given in a previous note the following are possible : — 22KC103= KCIO4+21KCI + 31O.2 = 3KCIO4+19KCI + 27O2 = 5KCIO4+17KCI + 23O2 = 7KCIO4+15KCI + 19O2 = 9KCIO2+13KCI + 15O2 = iiKCi04+iiKCl+ii02 = i3KC104+ 9KCI+ 7O2 = i5KC104+ 7KCI+ 3O2 making in all, with those previously given, sixteen equations (excluding the value O = O). Dr. Bottomley also introduced the subject of Mendele- jefPs recent paper on the compounds of ethyl-alcohol and water, published in the Journal of the Chemical Society for Proceedings. 91 October last, and referred to the Russian chemist's mathe- matical method for determining the presence of definite compounds. Dr. HODGKINSON made a communication on phenomena associated with diamond cuts on glass. Professor H. B. DixON made a communication " On the Union of Hydrogen and Nitrogen." He said: — In 1877, when I was demonstrator in Dr. Lee's labora- tory at Christ Church, Oxford, I assisted Mr. A. Vernon Harcourt in an experiment in which we endeavoured to bring about the combination of nitrogen and hydrogen by the silent discharge. Contrary to the statement of Mr. W. F. Donkin {Proc. Roy. Soc. xxi. 281) we found no trace of ammonia formed. Mr. S. Johnson has more recently expressed the opinion that nitrogen exists in two allotropic modifications, the first of which more easily unites with hydrogen than the second ; and that the action of heat on the first variety is to turn it into the second. According to this view, the nitrogen prepared by passing air and ammonia over heated copper and copper oxide (Mr. Harcourt's method) would consist wholly of the second or inactive variety, and would not unite with hydrogen to form ammonia. The existence, however, of these two varieties of nitrogen has not, I believe, been confirmed by other chemists. Mr. Harcourt has recently informed me that, finding the decomposition of ammonia to be appre- ciably incomplete when induction sparks are passed through the dry gas over mercury, he was led to the conclusion that the same sparks must bring about the union of hydrogen and nitrogen to an appreciable extent. This conclusion he has verified by experiment. I have repeated this experiment in a eudiometer with platinum-iridium electrodes 2 mm. apart. 30 cc. of a mixture of dry hydrogen and nitrogen* were collected over * The nitrogen was prepared from air by passing it over red hot copper. 92 Proceedings. mercury In the eudiometer, and 2 cc. of oil of vitriol were passed up to the top of the mercury. On passing sparks from the coil the mercury steadily rose in the tube, until after 35 minutes the liquid had risen to the wires, and only 5 cc. of the gases remained uncombined. Mr. Harcourt's experiment can therefore be readily shown to a class during a lecture. The experiment is really similar to that made by Deville, who found that hydrogen and nitrogen had the power of combining under the influence of the electric spark in the presence of gaseous hydrochloric acid. Deville con- sidered that the hydrochloric acid conferred the power of combination on the hydrogen and nitrogen : no doubt the hydrochloric acid in his experiment, as the sulphuric acid in ours, removed the ammonia as it was produced, and pre- sented the occurrence of the reverse change, viz. : — the splitting up of the ammonia into its constituents. In Mr. Donkin's experiment the sparks of the "silent discharge " were presumably of greater intensity than those employed by us in 1877, for ordinary induction sparks bring about a rapid combination, whereas our silent discharge was ineffective. Dr. Schuster gave the results of some researches by Prof Hann, of Vienna, and others, showing that the tem- perature in the centre of an anti-cyclone is higher than on its edge at heights above 1,500 feet, while at the sea level it Is lowest in the centre. Proceedings. 93 General Meeting, February 7th, 1888. Professor OsBORNE REYNOLDS, LL.D., M.A., F.R.S., Vice-President, in the Chair. Mr. Alderman W. H. Bailey, of Salford, and Mr. William Grimshaw, of Manchester, were elected ordinary members. Ordinary Meeting, February 7th, 1888. Professor OSBORNE REYNOLDS, LL.D., M.A., F.R.S., Vice-President, in the Chair. Mr. John Angell, F.C.S., F.LC, and Mr. ALEX HODGKINSON, M.B., B.Sc., were appointed Auditors of the Treasurer's Accounts. Mr. Charles Bailey, F.L.S., referred to the recent deaths of Dr. A. de Bary and Dr. Asa Gray, two of the honorary members of the Society ; the one a leading repre- sentative of botanical physiology in the eastern hemisphere, and the other the most distinguished botanical systematist of the western hemisphere. Both had been our guests in September last, and by their genial manners and their readiness to impart their great stores of knowledge, had endeared themselves to a widening circle of old and of new friends. Both had taken a prominent part in the proceedings of the Biological Section of the British Association's meeting in Manchester. Both of them left us to die in the homes of their fathers ; but ' To live in hearts we leave behind, Is not to die.' The younger of the two predeceased the elder, and many of us who welcomed him to Manchester parted from G 94 Proceedings. him with pain, from the knowledge we had of the mortal disease from which he was suffering, and which had just begun to take an acute form during the later days of his stay in Manchester. The Strassburg professor, Dr. Anton, de Bary, was born on the 26th January, 1 831, in the city of Frankfort, and, after holding the chairs of Botany suc- cessively at Freiburg, Halle, and Strassburg, died in the last-named city on the 19th January, 1888. During the last 35 years of his life of 57 years he contributed a succession of solid and original papers upon almost all departments of vegetable physiology, but with a decided bias towards investigations in the morphology and structure of the cellular cryptogams. These researches led to his selection by the Royal Agricultural Society of England to conduct an exhaustive inquiry into the nature and origin of the potato disease, which had been committing such ravages in these islands ; and though this appointment led at the time to a few ill-natured remarks about the inquiry being entrusted to a foreigner, the results justified the wisdom of the selection. De Bary's editorship of the weekly Botanische Zeihing (which comes regularly to the Society) showed how wide were his acquirements in all departments of botanical science. The book which perhaps more than any other would be selected by the speaker as illustrating his judicial mind and his insight into first principles is his " Comparative Anatomy of the Vegetative Organs of the Phanerogams and Ferns." This work discloses a vast array of isolated facts, splendidly marshalled, and largely based upon his own observations and illustra- tions (for he was an accomplished artist on wood) ; and yet in a treatise of such erudition, disclaiming criticism, he had the modesty to write, " that every word in this book has had a previous author, printer, and publisher"! Such was the spirit of the man \\hosc death is sincerely mourned by botanists of every nationality. Proceedings. . 95 The elder of the two, whom to know was to love — for he was as celebrated for his goodness as for his science — was a man who worked in quite different fields from de Bary. Though he was, confessedly, head and shoulders above the rest of American botanists, Botany could not claim Dr. Asa Gray as exclusively her own. Darwin appreciated his many- sidedness by writing of him and to him, " You are a hybrid, a complex cross of lawyer, poet, naturalist, and theologian." Born at Paris, Massachusetts, i8th November, 18 10, he died at Cambridge, U.S., 30th January, i S8S. The unique position which he held amongst American botanists largely con- trolled the direction of his work, for the wide extent of new territory constantly being explored on his native continent brought with it the duty of describing multitudes of new forms and species. Hence, it is in descriptive and geographical rather than in physiological botany that the monument of Gray's genius and labours will ultimately rest. But the personality of the man was greater than his work, and will never be forgotten by his contemporaries. A namesake of the speaker's, writing from Providence, and testifying from personal knowledge, says : " His presence among men was a benediction. In the summer classes, when the good Doctor entered the laboratory, he seemed to bring with him the blessed light of heaven. The room grew suddenly darker as he withdrew. All desired to see him. Strangers would wait in the garden to catch a glimpse of the venerable head at his favourite working window." A most grateful tribute of appreciative respect was paid to the ' old man eloquent ' on the occasion of his 75 th birthday, by the presentation of an elegant silver vase and salver, upon which were embossed the plants that are associated with his name. Notwithstanding his weight of years, Dr. Asa Gray was ever young in spirit, and he was as approachable to the little child as to the most diffident of his university pupils, as well as helpful and genial to all 96 Proceedings. who sought his help. He was among the most sprightly and merry of all our visitors to the British Association; and those of us who assembled to be photographed In the group of distinguished vegetable physiologists attending the meeting, will not forget the exuberance of spirits manifested by our revered friend respecting our desire that his charming wife should be included In the group. This photograph is already a memorable picture: in its centre Is the Society's former president and a present vice- president, Dr. W. C. Williamson ; on his right hand sits de Bary, on his left hand Asa Gray! Both are now gone from uSj and we shall see their living faces no more. Upon whom will Death next shoot his arrow? Whoever he may be, so let him have used his opportunities for enlarging the bounds of human knowledge to the extent of his capacity as did our two recent venerated guests! Mr. Bailey could not permit the occasion to pass without paying a tribute of respect to the memory and work of a British botanist who died almost at the same time as Dr. Asa Gray, viz., Dr. J. T. Boswell (formerly Syme), the well-known author of the scientific text of the third edition of " Sowerby's English Botany," which is a masterpiece of descriptive analysis and arrangement of our native phanero- gams and vascular cryptogams. Few men had paid more attention to the critical varieties of our native plants, or had so many of such plants passing through his hands for determination. His keen characterisation of their forms, and study of their fades, gave a great Impetus to the younger generation In Investigating the directions of varia- bility In the living plant, and of the comparative area which each species occupies in our islands. Laborious and' conscientious to a fault In all his botanical work, his opinions and verdicts. In consequence, were held in great esteem by all British botanists. Though living in the midst of many keen, and sometimes bitter, botanical Proceedings. 97 tournaments, he was entirely free from partisanship, and however keenly he would follow the merits of the contro- versy, he never took part in the strife. The speaker gratefully acknowledged how much his quiet influence had controlled the direction and spirit of his own studies, and none of his pupils would more sincerely mourn his death. Dr. Boswell was born in Edinburgh on the ist December, 1822, and died at his family estate, Balmuto, Fifeshire, on the 29th January, 1888. He lectured on botany for many years to the students of the Charing Cross School of Medicine, and afterwards at Westminster Hospital. His honorary degree of LL.D. was conferred upon him by the University of St. Andrews. Mr. Thomas Kay communicated a " Note on an erratic block observed during excavations for a sewer in Oxford Street, Manchester," by Percy F. Kendall, Assistant Lecturer on Geology in the Owens College, Manchester. Mr. Kendall said that the boulder was met with in the course of the excavation for a new sewer, and his attention was drawn to it by Mr. Jones, who was superv^ising the work on behalf of the Corporation, and to whom the geologists of the district were greatly indebted, as it was through his instrumentality that nearly all large boulders placed in our public Parks have been secured. The stone was found embedded in the base of the boulder clay, just at the junction with an underlying bed of gravel. Its extreme dimensions were about 9ft. 6in. x 7ft. 4in. x 5ft. loin. Such large boulders offered much more striking evidence of ice-transport than those of small size, as we know of no other natural agent competent to effect their removal to great distances from the parent rock. An inspection of the rock showed that it was identical in character with the most abundant rock among the smaller boulders of the neigh- bourhood, viz. : a volcanic rock of the andesitic type. As to the place of origin of the rock — he had found among 98 Proceedings. the small specimens some which contained fragments of rhyolite lava enclosed in andesite, and as such an associa- tion is of rare occurrence in Britain, he thought the fact that andesites and rhyolites were to be seen in the country about Honister and Coniston, might be accepted as evidence of the derivation of the boulder from that part of the Lake District. He had indeed seen specimens which were indistinguishable in appearance from the example under consideration. The specific gravity of the rock was about 275, which would indicate a weight of about i7olbs. per cube foot. The weight of the boulder might be taken as between 20 and 30 tons. He added some observations upon the question of a vertical circulation in the glacier-ice, which might possibly account for the fact recorded by Mr. J. G. Goodchild that transported blocks have been found at an altitude of 1,000 feet above the parent rock, though at a distance of 5 or 6 miles. Mr. Faraday alluded to the perched blocks on Norber, a spur of Ingleborough, and suggested that the Craven district was worth considering as a possible source of travelled blocks found in this neighbourhood. Proceedings. 99 MICROSCOPICAL AND NATURAL HISTORY SECTION. Ordinary Meeting, February 13th, 1888. The President, Professor WILLIAMSON, F.R.S., in the Chair. Mr. H. L. Earl, B.A., Manchester Grammar School, was elected an associate of the section. There were exhibited : — By Mr. R. C. CUNLIFFE, — Volcanic dust, from Krakatoa in the Straits of Sunda, and from Tarawera in New Zealand. By Mr. Thos. ROGERS, — specimens of the pearl mussell, Unio margaritifer, from the river Lune ; the only recorded locality for this species in Lancashire. First discovered by David Dyson about forty years ago, and re-discovered by Robert Standen in 1887. By Mr. H. C. Chad WICK, — specimens of three species of Bagnla. By Mr. H. Hyde, — specimens of Chalk, from the Brighton coast, and from the Channel tunnel. By Mr. J. C. Melvill,— the P of a Hymenopterous insect from West Columbia, of which the ovipositer was of the extraordinary length of 5j^ inches, the insect itself being less than three-quarters of an inch long. The President described two forms of reproductive gemmules developed on the roots of two species of mosses grown in one of his hot-houses. One of these mosses was Webbera nutans, on which these gemmules were pyriform. The other was an undetermined moss, on which the gemmules were circular like those fio-ured in the LeJirbucJi of Sachs. TOO Mr. Cosmo Melvill on By Mr. John Boyd, — two quaint old microscopes. One presented to the section in 1873 by Mr. Rideout ; the other, believed to be John Dalton's, made by B. Martin, London, which is the property of the Society. Dr. HODGKINSON exhibited and explained, "A pris- matic chart for determining the characteristics of interference colours." Notes on a Small Collection of Mosses from Mauritius. By J. Cosmo Melvill, M.A., F.L.S. (Received February 13, 1888.) For the last three or four years I have from time to time received various botanical collections, mostly Crypto- gamic, from the island of Mauritius. In 1885 two very interesting parcels of Marine Algae arrived, which I submitted to Prof J. G. Agardh, of Lund, Sweden, the result of his investigations being that no less than twelve species — and these among the most conspicuous and showy kinds lY^ainly — w^ere described by him as new to science. And last July I came into possession of a collection of Musci from the same source, with a few Ferns and Hepaticae, intermingled. The ferns sent are very meagre; Mr. J. G. Baker, F.R.S., of Kew, detected one common species of Polypodium and three of Trichomanes: — T. cuspidatum (Willd) = Bojeri (Hooker) endemic to Mauritius and Bourbon, T. Filicula (Bory) = bipunctatum (Poiret) which latter name has priority, a very widely-distributed fern, and T. trinerve (Baker), a recently described and rare species, not occurring elsewhere. The Mosses have all been carefully examined by Mr. Henry Boswell, M.A., of Oxford, one of our highest Mosses from Mauritius. i6i authorities on this group of plants, and for the following discriminations my best thanks are due. He informs me that such collections from this island have very rarely come hitherto to this country, and that the only collectors there during the past twenty years have been Mr. Pike and M. Robillard, both well known for their researches amongst the Mollusca and other branches of Zoology as well. From M. Robillard's specimens most of the known endemic Mauritian mosses have been described, mainly by Herr C. Mtiller. Many of these will be found to occur in the collection now under notice. It is to be regretted that very few show any signs of fructification. Only one species, Hildenbrandtiella nitens (Boswell MSS.) is actually a novelty, but several are almost unknown in Herbaria. This will probably be described in the Toiirnal of Botany before many weeks elapse. MUSCI {a) ACROCARPI. Fam. : DicranecB. 1. Campylopus brachymastix (C. Mtiller). 2. „ chlorotrichus „ 3- n sp. 4. Leucoloma amblyacron (C. Miiller.) 5. „ persecundum „ 6. „ sinuosulum „ Fam. : Leucobryece. 7. Octoblepharum albidum (L). Fam. : OrthotricJiece. 8. Macromitrium aciculare (Schweg). 9. „ sp. nisi in fructu hand cognoscendum. 10. „ sp. I02 Mr. Cosmo Melvill on 11. Macromitrium laxotorquatum (C. Mliller). 12. Schlotheimia Robillardi (C. Mliller). Fam. : Bartrainiece. 13. Philonotis tciiuicaulis (Hampe). Fam. : Bryccu. 14. Bryum nanorhodon (C. Miiller.) 15. „ sp. 16. Rhizogonium spiniformc (L.). Musci {b) Pleurocarpi. Fam. : HypopterygiecB. 17. Hypopteryglum pugiunculus (Boswell MSS.). [Madagascar, 1880 — forsan H. Nossibeanum C. Mliller.] Fam. : RJiacopihce. 18. Rhacopilum Mauritianum (Hampe). 19. „ sp. Fam.: Neckerece. 20. Pterigynandrum fabronioides (C. Mliller). Fam. : Mcteoricce. 21. Lepyrodon Mauritianus (C. IMlillcr). 22. Hildenbrandtiella nitens (Boswell MSS. nov. sp. 1887) 23. „ puccinigera (C. Mliller). [There are, including nitens, but three described species of this circumscribed genus.] 24. Meteorium (Papillaria) cuspidiferum (C. Mliller). 25. „ (/Erobryum) pseudocapense (C. Mliller). 26. Porotrichum Robillardi (C. Mliller). 27. „ sp. hand dclcrm, Mosses from Mauritius. 103 Fam. : Stereodontece. 28. Ectropothecium nanocristacastrensis (C. Mliller). 29. „ sp. hand determ Fam.: Hypnece. 30. Jaegerina solitaria (C. Mullerj. [ = Hypnum solitarium (Brld.)] 104 Proceedings. General Meeting, February 21st, 1888. Mr. Charles Bailey, F.L.S., in the Chair. Mr. Alfred Ree, Ph.D., F.C.S., of Middleton, near Manchester, and Mr. Alfred D. Hall, of the Hulme Grammar School, Manchester, were elected ordinary mem- bers. Ordinary Meeting, February 21st, 1888. Mr. Charles Bailey, F.L.S., in the Chair. Mr. F. J. Faraday, F.L.S., exhibited fragments of the perched blocks on Norber, a spur of Ingleborough, and other specimens of the rocks of the vicinity, and gave a preliminary sketch of a new hypothesis to account for the peculiar position of the perched blocks, with suggestions as to the influence of subsidence in the production of some of the remarkable features of the district, and the bearing of the hypothesis on the question of geological time. Change of Incidence of Small-Pox. 105 On the change of incidence of Small-Pox at different ages during the years 1848-86. Part I. By R. F. Gwyther, M.A. Received February 21st, 1888. It may interest the Society to see to what extent the change of incidence of small-pox in regard to age, which was noticed by our late Secretary and Editor, has con- tinued to act, and I offer to the Society some tables which I have prepared to illustrate the way in which that change has displayed itself When I had nearly completed the preparation I found that the subject had been treated by the Registrar General in his report for 1880, and by the Medical Officer of the Local Government Board in his report for 1884, and each of these reports contains an extended exami- nation of the causes acting. My reason for preparing these tables was, therefore, considerably weakened, and I should not have brought them forward except that the tables are fuller, and seem to indicate one or two points which I have not seen noticed. The tables which I have prepared give the death rates calculated for 1,000,000 living at the ages given at the top of each column. I have taken so large a number because, to many, whole numbers give a more intelligible picture than places of decimals. I have kept the results for males and females separate, because there is a considerable difference between the inci- dence of small-pox on the two sexes at certain ages. The subject of this paper is well illustrated by an excel- lent and interesting paper by Dr. J. C. Mc.Vail, read before the Philosophical Society of Glasgow, in 1882, "On the prevalence of small-pox in Kilmarnock in the 36 years, H io6 Mr. Gwyther on the 1 728- 1 764," in which he shows that epidemics occurred regularly at somewhat over 4 years ; that the victims of each epidemic were almost entirely taken from those born since the preceding epidemic ; that the rate calculated on this basis was a death rate of 126 per thousand ; and that the deaths in the first four years were roughly in the rate of incidence shown by 0- 118 146 136 lOI 62 where the rates in successive years are progressively too low, because I have not allowed for diminution by deaths from other causes. Comparing this with the corresponding columns of Table I., we see that the maximum infant death rate is now very decidedly within the first year, and probably within the first six months of life. As the epidemic of 187 1-2 is unique in the years covered by the Registrar General's reports, I have considered it separately in Table II., and during that epidemic we see that the infantile death rate had begun to rise again in the fifth year, and we shall see later that the rise was more markedly continued during the next five years. The decrease of death rate is well marked during the course of years that I am considering, except in the fourth year during the epidemic of 187 1-2. In the ages from 5-10 the diminution of death rate is well marked though less than the infantile rate, but during the epidemic of 187 1-2, the increase of the death rate at this age was very considerable as is well shown by con- sidering Table III. After passing the age of ten, the reduction in death rate is not so considerable as to seem to require any special examination. Change of Incidence of S mail-Pox. 107 I 0 10 Q-oo .s ^' ^ O o ^ ^ ^ 1 1? o ^ .2 S ■■X ^ fi 00 o !U CI ^ "^ Xi A Zi -. ■^^ ■^ ,^ •^ .« c^ ^ ■?^ « V, « ^ I f ^ ■^-^ CO I 2^ I - " i oo 1 £ c 2" f^ c B . c c c Z 2 1 s t K ^ 1 ^ ■^ 1 M 1 0^ - 1 S 1 " 1 ^ 5 1 ? - 1 'i ! s- % 1 s IS7I-2 Other years. ^ ^ ^ ^ ^ ^ - ! Is ON O ^ w '_; >» ^ rt r;; (U m 0 ij5 ^ CJ ^ -^ •^ ^ 0 a> 0 a> >.^ N 00 0 •-• r-i ■t:; 0 fl rf ^ ON c ^ c 00 •^ a> in >- Change of Incidence of Small-Pox. 109 III- — Tables givins: ratio of death rate at different ages to the death rate at all ages in different sets of years. MALES. -5 5- 10- 15- 20- 25- 35- 45. 55-65-75 1848-58 4-6 I'l •3 5 •4 •3 •2 •2 •3 •5 •I •2 •2 •4 1859-66 37 •9 •3 •5 I* 7 •5 •3 •4 •8 1867-76 1877-86 2-3 1-6 1- 7 •4 •6 7 •8 1-4 13 I- 1-3 7 I- FEMALES. 1848-58 5-4 1-2 '3 ■ — 4 '3 •I •5 •I •2 •3 •6 •05 •05 1859-66 4-5 I- •4 •6 •6 •4 •2 ___ '4 •I •2 •3 1867-76 2-9 1-3 •6 •8 I- •8 1877-86 2-2 '9 •8 i-i 1-3 i-i •8 MALES. 1871-2 2*1 1-2 •5 7 I '4 ... 7 •5 '3 •2 Rest of decade. 27 •9 '4 7 I '3 I- •6 •4 •3 •2 FEMALES. I87I-2 2-6 1*4 •6 •9 I- •8 '5 '3 •2 •2 •I •I Rest of Decade. yz I- '5 ■6 I 7 •5 •4 IV. — Comparative incidence of small-pox at different ages on the two sexes. ■5 5- 10- 15- 20- 25- 35- 45. 55-65-75 1848-58 I- I'l .• I '4 1-8 2* ••9 2 '5 2-4 2-4 17 1*5 3' 1859-66 !• I' •• I'l 2- 2- 1867-76 I- I- 1- I-I 17 1-8 17 1-9 1-5 1-8 i'5 1-5 17 2- 1877-86 I- 1*2 •9 •• .•5 .7 no Mr. Gwvther on the In Table III. I have formed the proportion of the death rate from small-pox at the several ages to the death rate at all ages over the same period of time ; we there see that, besides the maximum proportion at the ages under five (which has been diminished), there is a second maximum between the ages of 20 and 25. This appears from this table to have been increasing, but the increase is not more than would be accounted for by the diminution of the infantile rate. If we pass beyond the age of 35 the increase of the death rate is obviously an actual increase. To account for this it is in the first place obvious from such statistics as I have quoted from Dr. Mc.Vail's paper, that small-pox epidemics gave a considerable, if not com- plete, immunity to those who passed safely through one or two of them — a more lasting immunity than any that can reasonably be claimed from vaccination. If our record went further back we could gauge the effect of this most accurately. If this is, as seems to be the case, not an efficient reason to account for the rise of adult death rate from small-pox, and it is claimed that small-pox has increased in virulence (and there appear to be other than the statistical reasons for imagining this to be the case), the effect of this claim is to make the diminution in the death rate of early years more marked. All the consequences of these hypotheses can only be truly estimated by the physician, and so I proceed with the discussion of the statistics. In Table IV. I have calculated the ratio of the death rate of males to females at the several ages during the periods which I have been considering. From this we see that up to the age of 20 the inci- dence upon the two sexes has been constant and practically identical. Beyond that age the disease has fallen consider- ably more heavily upon the males, the ratio being fairly Change of hicidence of Small-Pox. 1 1 1 constant, and somewhat less than 2, up to the age of 45. From 45-65 the discrepancy seems to be diminishing. The unsteadiness of the numbers between 65-75 is probably owing to the small number of actual deaths at those ages. The cause of this difference is not easily seen, but the effect appears very markedly at the age of 20 years, and continues fairly constant in later life. Concluding this paper, which is merely descriptive, I may sum up the results to be — 1. That during the last 39 years, from some causes, the death rate of children from small-pox has been greatly diminished, the rate of diminution decreasing with age. (I.) 2. That above the age of 35 this diminution is actually changed into an increase of the death rate, in spite of the decreased death rate at all ages. (I.) - 3. That, considering the death rate at all ages in com- parison with the general death rate, the diminution in the proportionate rate does not continue beyond the tenth year and above 20 years the proportionate death rate increases much more rapidly than the infantile rate decreases. (III.) 4. That during the severe epidemic of 187 1-2, the pro- portionate death rate at higher ages was not far from normal, but that between the ages of 4 and 10 It rose to about ^^ more than the normal proportion, while among children under 4 the proportionate rate was considerably diminished. (III.) 5. That the incidence of small-pox on the two sexes seems to be identical up to the age of 20 years, and that after that age the death rate for males is about double that for females. (IV.) 112 Mr. Henry Holden on the A method of calculating the Electrostatic Capacity of a Conductor. By Henry Holden, B.Sc, Bishop Berkeley Fellow in Physics at the Owens College, Manchester. Communicated by Prof. Schuster, F.R.S. (Received February 21st, 1888.) The following paper contains a method for calculating the capacity of a conductor, the condition of the dielectrical medium being primarily considered. This method seems to be the most natural one, and affords a simple explanation of the meaning of the capacity of a conductor under any circumstances. In works on electrostatics the capacity of a conductor in the presence of other conductors is generally defined as the quantity of electricity necessary to raise its potential by unity, all the other conductors being connected to earth. It is noted that this capacity does not depend on the nature or mass of the conductor, but on its external shape, and on the shape and position of the neighbouring conductors (not on their nature or mass), and that the nature of the dielectric between the conductors also affects the capacity of the conductor considered. Thus it is evident that the so-called capacity of a conductor is not one of its true physical properties, and we may infer that a conductor has really only an indirect influence in determining the value of what is known as its capacity'. ^ The first problem in calculating capacity usually considered in books on Electrostatics is the case of a charged sphere at an infinite distance from any other conductor. The capacity of such a charged sphere is generally calculated somewhat as follows. It is first assumed that only the quantity of electricity on the sphere need be considered since all other quantities of electricity are, by hypothesis, infinitely distant. A previously-found expression for the potential at a point is then used to prove that the potential at the centre of (and there- fore throughout) the sphere is V = ^ where V is the increase of potential at the centre of the sphere of radius R due to a quantity Q of electricity on the surface of the sphere. Substituting for Q its value CV (where C is the capacity of the body) it follows that C = R. We are afterwards told that if the medium surrounding the sphere be not air, the cajxicity is ecjual to KR where K is the Electrostatic Capacity of a Conductor. 1 1 3 It is known that specific inductive capacity bears the same relation to flow of force'- as conductivity does to a flow of electricity^ Consider, therefore, the problem in current electricity corresponding to the above electrostatical one. An anode A is placed in a conducting medium in which are placed several kathodes B, C, etc. Then in the phraseology generally used for capacity, the conductivity of the anode A would be spoken of, and it would be said that the conductivity of A depended neither on the nature nor the mass of A, B, C, etc., but only on their external shape and their relative positions. Finally it would be said that if the medium between A, B, C, etc., was not a certain one, the result obtained by calculation from this method of considering the phenomena would have to be multiplied by a certain number, fixed for the medium in question. Such a mode of viewing the facts is evidently irrational, and tends to withdraw the attention from the real principle, namely, that the conductivity under con- sideration is that of the medium, and that the function of the electrodes is simply to bound the portion of the medium which is traversed by the current. Adapting this mode of description to electrical capacity, tJie so-called capacity of the conductor is the capacity of that portion of the dielectric bounded by the conductors and traversed by the lines of specific inductive capacity of the medium, but it is not easy to see, from the above assumptions, why this should be, or in other words, if only the quantity of electricity on the suface of the sphere need be considered, why the potential at the centre of the sphere due to a quantity of electricity on its surface should depend on the nature of the medium outside the sphere. The advantage of the method now advocated is that the medium between the <:harged body and the corresponding induced charge is always kept in view. " Flow of force along an air tube of force = F^fS where ^S is the perpendicu- lar section of the tube and F the mean value of the force on that section. -/i^-7rdq where dq is the quantity of electricity at the commence- » We have Q = C(Vi - V.J ment of the tube, or 4crQ = 4'77C(V, -\\) or Flow of force = 4^0 x diff. of pot. 114 Mr. Henry Holden on the force, I shall show later how it may be calculated on this supposition. Taking this view of the matter, it is evident why the so-called capacity of a conductor is not altered by any changes in the conductor (such as change of material, or change from a solid to a hollow conductor) which do not alter the direction and extent of the lines of force. The capacity of a certain portion of a dielectric, bounded by lines of force and equipotential surfaces, may be therefore defined as the qtiantity of electricity^ zvJiich has to be dis- tributed over one end {an equal but opposite quantity being on the other e?zd)y in order to cause unit differejtce of potential betiveen the two ends, and we may call the capacity of a portion of a dielectrical medium of unit length and unit section the specific capacity of that dielectric ; a term corres- ponding to specific conductivity in the case of a conducting medium. Each dielectric will have its own specific capacity, and the ratio of this to that of air will, of course, be the specific inductive capacity of the dielectric considered. Method of calcidating capacity. Consider a charged conductor A at potential Va in the presence of other conductors B, C, etc., at potentials Vb, Vc, etc., and suppose that the dielectric medium between has a specific inductive capacity = K. 1 The distribution of the electricity is supposed to be such that the lines of force proceeding from one quantity of electricity to the other bound the portion of the dielectric under consideration. Electrostatic Capacity of a Conductor. 115 Consider an elementary tube of force proceeding from the elementary quantity of electricity dq on A: this tube will evidently end on another conductor, B, and enclose there a quantity of electricity = --dq. Let dS be the area of a perpendicular section of this tube, at a distance = r, measured along the tube, from any convenient point. Then if F is the value of the force at ^S we have, by the theorem of the flow of force, Iv dY \Tzdq dr ~ K^S -^V. K dr ^itdq dS or, integrating along the tube of force, from A to B, we have^ since dq and K are constant along this tube, y-2 I :vi- 47rdq K.(Vi-V2) fdr^ 4Trdq K(Vi-v,)-y = rdr dS or if the whole quantity of electricity on A which is at the base of the tubes of force proceeding to B is q, we get, since (Vi - Vg) is constant for these tubes of force, K(Vi-V,)= rdr^ :j ds where -— has to be inte^-rated alon^ a tube of force between limits of r given by the surfaces of A and B, and then the reciprocal of this integral has to be integrated so as to include all the tubes of force proceeding from A to B. Again, ^ is the capacity of that portion of the VI- Va ii6 Mr. Henry Holden on the dielectric enclosed by the tubes of force proceeding A to B = Cab, say and .". 4^' Cab K from We should get similar expressions for the portion of the dielectric enclosed by the tubes of force proceeding from A to the other bodies, so that summing up so as to include all the dielectric through which the lines of force from A pass, 47rC K % dr_ The following examples will show the applicability of the method. Ex, I. Concentric spheres, radii Ri and R2. The lines of force are radii, and dS = rWw ; the limits of r being Ri and R2 R2 R2 /dr^ _ r dr _ 1 f 1 i\ dS ~ J r^~ dio\Ri~ R2J Ri Ri The inverse of this has now to be integrated so as to in- clude all the tubes of force proceeding between the two Fig. 2. spheres ; the limits of dio are .*. 0 and 47r, or j\.iK.2 4^ R1R2 R2 — Ri R2 ~ Ri or C 47r R1R2 R2- Ri R R1R2 R2 — Ri £x. 2. — Parallel planes, surface S, at distance e. Electrostatic Capacity of a Conductor. 1 1 7 Assuming the lines of force to be parallel, the section of the tube of force is evidently independent of r or 47rC _S K ' ~ e C = _KS 47rd or From this example it is seen that the specific capacity of a dielectric (as defined above, namely, the capacity of a unit cube) is equal to — , and that the capacity of a portion of a dielectric is got by multiplying the specific capacity by the cross section, and dividing by the length of the dielectric, assuming that the cross section of the portion of the dielectric considered remains uniform. If it does not, we must have recourse to a process of integration, as shown above. Ex. 3. — Coaxal cylinders, of length /, and radii Rj and R2. In this case, the lines of force are evidently radii between the two cylinders. Con- sidering a tube of force formed by two planes pass- ing through the axis, we have J R.. d^ ~ Id^^^^^ Ri The limits of 0 are evi- dently o and 2ir. Fig:- 3- ii8 Mr. Henry Holden on the m 27r/ dr 1 Ra . R2 47rC K or C = 2-1 Ri K./ lO£^ ^;ir. 4. — Cylinders of circular section, one inside the other but not coaxal. Fig. 4. Fig-. 5- Let A and A' be conjugate points with respect to the circular sections of each of the cylinders. Then, it is known that the lines of force between the cylinders are arcs of circles passing through A and A', each line of force being therefore defined by the condition 0= constant (see Fig. 4). Let P be a point on a line of force, and suppose that the direction of the force at that point makes angles a and o! with AP( = p) and A'P( = pO respectively. Then since dr is Electrostatic Capacity of a Conductor. 119 measured in the direction of the force, and ^S perpendicular to it, we have (see Fig. 5) drcosa = dp drcosa-dp' ^Scosa = Ipdu) dScosa = /p'dio' if / is length of cylinders. . dr do do' dS tpdu) /f » dio' - du)') dp\ 9) But (see ■ Fig. 5) (1) — w ~ = 6 and .' . du)-doj' = dd • dr _ \ /dp dp\ " dS~Idd\t~ p) Integrating along a line of force, 0 being therefore con- stant: and denoting limits of p and o corresponding to the two cylinders by the suffixes i and 2 fdr I / 02 - p2\ I - Oo p\ = T^7.l0g f>'2 Pi IdQ ""-' But if Ri and R2 are the radii of the two cylinders, and Di and D2 the distances of h! from their centres £2^ _ R2 p]_ _ Ri p'2 D2 p'l Di by the properties of conjugate points and . fd^ _J_-, R2 Di "J ds'W^^'D^ ' r; The coefficient of 0 being thus independent of d, it is easy to perform the second integration. I f /dd 2-rtl V since limits of 0 are 0 and 27r ..by formula -j^ = -^ 1 20 Electrostatic Capacity of a Conductor. K/ C = , R2 Di If the cylinders are coaxal, the external conjugate point is at an infinite distance, or and the usual expression for the capacity of co-axal cylinders results. If the external cylinder becomes a plane, at a finite distance from the other cylinder, its centre is at an infinite distance, or K/ and .*. C 1 ^1 2log^; If the distance between the centres of the cylinders and their radii are given, Di and D2 may be easily expressed in terms of these quantities. Thus, it is seen that this method is easily applicable to all the ordinary problems in capacity; with more complicated cases difficulties arise in effecting the requisite integrations,, as must necessarily be the case whatever method is adopted. Change of Incidence of Small-Pox. \ 2 1 Ordinary Meeting, March 6th, 1888. Professor W. C. WILLIAMSON, LL.D., F.R.S., Vice- President, in the Chair. Mr. J. R. H. Williamson exhibited an 800-candle power Edison-Swan incandescent lamp, requiring about 18 to 20 amperes of current at an electro-motive force of 112 volts or 2j4 watts per candle. Mr. Williamson explained the advantages offered by these high candle-power lamps over the " arc " lamps. He also exhibited a new form of American frictional electrical machine for exploding dyna- mite in blasting, and capable of exploding 1,000 fuses at once. On the change of incidence of Small-Pox at different ages. Part II. By R. F. Gwyther, M,A. (Received March 6th, 1888.) In communicating to the last meeting the tables showing the change of incidence of death by small-pox at different ages, I said that the change might possibly not be altogether accounted for by our changed sanitary and other arrange- ments. If this is the case, the question would only be partly a question of statistics, and it appears desirable to consider whether we could attribute the change entirely to our changed condition without having recourse to an assumed increase of the virulence of small-pox. In a paper, of which I shall make a large use, I find that in 1760 it was held as a medical opinion that small-pox became more fatal beyond the age of 20 years. This strengthened my own opinion, I 122 Mr. Gwyther on the that the change of incidence is normal, and in this note it is intended to collect some evidence on that point, leaving the medical question for competent authorities. In the first place I am going to compart the death rates of vaccinated and unvaccinated up to the age of 20, which I think we may take as beyond the extreme limit of pro- tection by infantile vaccination. I am aware that such statistics are to some extent untrustworthy, but I am not going to make my argument depend on the actual numbers so much as on the general character of the series which the numbers show. In the Report of the Medical Officer of the Local Government Board for 1886, there are tables showing the deaths from small-pox in London during the years 1884 and 1885, of inhabitants born in London. Since 1872 the proportion of the inhabitants of London not finally accounted for in the vaccination returns has varied from 57 per cent to 9'3, and it appears that we shall not be far wrong in assuming that i in 12 in London escaped vaccination. Deaths fro/n S /nail- Pox of Metropolitan Inhabitants horn in the district. VACCINATED. Ages. O-I 1-5 5-10 10-15 15-20 20-30 30-40 40-50 50-60 1884. 5 7 5 5 14 14 13 3 I 1885. 7 10 6 1 II 23 23 22 I I UNVACCINATED. Ages. o-i 1-5 5-10 10-15 15-20 20-30 30-40 40-50 50-60 1884. 89 57 20 12 7 T J 2 0 I 1885. 128 78 51 19 7 13 I 0 ° Looking at the progression of these numbers of the unvaccinated, one is distinctly reminded of the course of Change of Incidence of Small-Pox. 123 the death rate at different ages at the time when previous attacks by small-pox conferred the only immunity from future attacks. And if the death rate on the vaccinated community taken in the proportion of about 1 1 to i had been at the same rate, up to the age of 20, the death rate at the ages beyond, even if we do not lower it on the plea of immunity conferred by small-pox, would not appear un- reasonably large. Since 1880 the Registrar General's Returns have separated the deaths from small-pox under the heads Vaccinated, Unvaccinated, and No Statement, and these returns show the same kind of progression as I have illus- trated by the table above, and I know no reason why these should not be taken as representing the general features of the incidence of small-pox on the vaccinated and unvac- cinated when equally exposed to it as during the said years in London. It seems desirable to apply some amount of calculation to make the comparison more obvious, and to that I now proceed. My attention was called by Dr. Bottomley to a Memoir by Daniel Bernoulli among the Memoires de I'Academie Royale des Sciences for the year 1760, entitled "Essaid'une nouvelle analyse de la mortalite causee par la petite Verole," &c., which is very interesting both on account of the at- tempt to find a mathematical expression for the death rate from small-pox, and as giving a good idea of the virulence of the disease and its incidence at different ages at that date. As it may interest members of the Society, and will certainly illustrate the change of the incidence of the dis- ease between that date and this, I ask leave to add this note to my paper lately read. Two short passages I will quote at length : — "J'ai dit d'abord que la petite verole naturelle enleve la huitieme ou la septieme partie de ceux qui en sont malades. 124 Mr. Gwyther on the En Angleterre, on adopte assez communement la derniere proportion : dans d'autres pays il ne parait pas que la mor- talite de cette maladie soit si grande. " Quant a la proportion qu'il y a de la mortalite de la petite verole a la mortalite entiere du genre humain, on a suppose communement en Angleterre comme i a 14 : il ya la-dessus des listes rapportees par M. Susmilch, qui mar- quent qu'a Londres il est mort de la petite verole 19,745 sur 260,875, ce qui donne la proportion i a 13V5; a Vienne, cette maladie a enleve 1,083 sur 13,521, c'est i sur I2j^; a Berlin, 586 sur 6771, c'est i sur ti^; a Breslau, 431 sur 4,579, c'est I sur 10^. Mais ces dernieres proportions n'ont ete prises que pour deux et trois ans pendant lesquels il peut y avoir eu une epidemic un peu forte." I am unable to state what is now regarded as the average ratio of deaths to cases, but during the last ten years the ratio of deaths from small-pox to the total deaths has been about i to 286, and during the epidemic "un peu forte" of 1 87 1 -2 the ratio was about i to 23^. It is necessary to note this change to understand at all how it was possible that his mathematical results which I am about to notice could have seemed to represent in any respect the rate of mortality at the time. It must be borne in mind that the mortality tables which they had were very defective ; but the objections to the paper seem to have been founded on minor points, and not on any doubt of its general representation of the facts of the case, while at the present time the divergence of his results from actual expe- rience would be patent to everyone. The investigations of which I speak are two, which I shall give in only slightly modified form : — I. To find the ratio between the number of those at an age X who have not yet had small-pox, and the total num- ber of survivors at that age. Let the age be expressed by x, the number of survivors Change of Incidence of Small- Pox. 125 at that age by g, the number of these survivors who have not had small-pox by s : suppose that during the unit of time in which x is measured, on the average out of n persons one takes small-pox, and that out of m persons who take small-pox on the average one dies, and let us suppose that m and n are constants at different ages. Then the number of those who take small-pox durin^r Sox ^ the time dx is — , and the number for whom it ends fatally ^^ '^n Consequently those who die from causes other than small-pox is -^5-^. Taking the proportion of these deaths which correspond to the number s who have not had small-pox, we get set, s-dx t, uint Then -ds denoting evidently the number who take small-pox and do not die, during the time dx, we have the equation _ , _£££ sdt s-dx n t, mnt, Although this equation contains three variables, s and 'i only appear in the form of the ratio s'X-=q and we get inndq =dx mq - I in + I And we can determine the constant by supposing that at birth s = ^,q=\, hence m (m- i)f^ + I From this relation Bernoulli easily forms theoretical tables which it appears that he thought fairly represented the small-pox mortality at the time. Putting m and n each equal to 8, he considers that his tables give good results. 126 Mr. Gwyther on the The rate of death from small-pox calculated from it he thinks relatively too high for children under one year, and proposes to account for it as a difference rather moral than physical and attributes it to the slight communication which such children have with the outside world. As the difference would relatively now seem to be in the other direction, we may have to consider a change of manners as partially accounting for it. To return, it is obvious from the method of obtaining the equation above that it would only be true even approximately for a disease in an endemic and not an epidemic form, and therefore if v/e are going to lay any weight on Halley's Tables, with which Bernoulli compares his formula, it must be on the hypothesis that, although in places small-pox might be epidemic, the general character of its incidence upon the peoples from whose death rate the tables were founded was, on the average, that of an endemic disease. The results drawn from it would neither agree with modern tables nor yet with such tables as those given by Dr. McVail in the paper quoted above, though they would agree with the latter in limiting the excessive inci- dence of small-pox to youth. Comparing the death rates in the first and the second years as found from this formula, they appear to be in the ratio of 13-1 to 12-4, and, as I stated before, Bernoulli is forced to consider the first too high. It is so certainly if we may compare it with the Kilmarnock death rate ; but at present the ratio in England appears to be about 3:1, and the heaviest death rate appears to be compressed into the first half-year of life, during part of which children are in no way protected. Considering further the death rate from small-pox during the first five years of life, Bernoulli con- cludes that he is not far wrong in considering it about one- tenth of the total death rate during those years. A similar comparison during the years 187 1-2 gives us about one- thirtieth, which is certainly very heavy ; but on the average of the last twenty years we find it is a very small fraction. CJiange of Incidence of Small-Pox. 1 27 Passing to the other limit to which BernoulH thinks that his theory appHes, we find that out of 1,000 living at the end of the first year of life there would be 32 only at the age of 24 who had not already had the small-pox, and even without allowing for deaths by other diseases, only one on an average at the age of 49. On account of the smallness of these numbers Bernoulli does not attempt to alter his theory to deal with them, but limits its application to about 20 years. In the then state of affairs the argu- ment of the small number treated of was a sufficient reason for this neglect ; but for us it is the reason for supposing that the theory could not be pressed further that is most important. I quote it: "Ce n'est qu'au-dessus de cet age qu'on suppose ordinairement la petite verole commencer a devenir un peu plus dangereuse." As far as I am able to judge from non-professional literature on the subject, as for instance Mr. Baxendell's paper before this Society, later writers on the subject have been accustomed to speak of small-pox in past times as having been fatal mainly in youth, and not to have been a disease greatly incident on manhood and age. As far as the paper considered is evidence, the facts were different Small-pox appears to have been considered more fatal with advancing years, and the death rate at those ages was only kept low by the immunity conferred by previous attacks of small-pox. We must consider to what extent the paper of a mathematician can be considered evidence on this point. It seems to depend on the position and eminence of the writer, who could not afford to be convicted of false repre- sentation in his paper, on the general character of his scientific writings, on the means he was likely to have to obtain the recognised views of the medical profession, and on the fact that, as far as one can gather from the intro- duction written five years later than the paper, the paper 128 Mr. Gwyther on the was not attacked on the score of not representing the actual facts of the case. Passing on to Bernoulli's second Investigation — Theorem II. — To find the ratio of the number of those who would be alive at any age, If death from small-pox was prevented, other circumstances remaining the same, to the number who would be alive on the hypothesis of the pre- vious theorem. The other letters retaining their original significations, let K denote the numbers living at the age x under the changed circumstances. The total mortality during the time dx will now be -l{dt, which we must write ~ d'Q. , dii dl __ sex substituting for sjt, and Integrating we get 4 — X v. {m- i)e" + I and thus the required ratio has been found. Now Bernoulli's object was to show to what extent life would be saved by adopting the system of inoculation, but we may apply his results to the consideration of other cir- cumstances not foreseen by the author. Take the two most extreme cases to make a comparison. Imagine a locality in which small-pox Is epidemic for x years, and that, in another locality having the same number of Inhabitants, from superior sanitary or other reasons small-pox does not appear for x years, but that the inhabitants have no immu- nity against small-pox in case it should be introduced, we see from what I have proved above that the ratio between the numbers subject to small-pox In the two places would be Change of Incidence of Small-Pox. 129 To take an instance, making use of the numbers which Bernoulli found to suit the case fairly in 1760, and taking JIT = 24. Out of 1,000 who were living at the end of one year there would be 32 subject* to small-pox at that age in the one case, and about 650 similarly subject to it in the protected locality, and, therefore, if small-pox attacked the latter locality they might expect for a time a death rate at the age of 24 about twenty times as great as the death rate at a corresponding age in the locality where small-pox was epidemic. In addition to this we should take into con- sideration the more fatal character of the disease when incident on adults, as in the latter case compared with the former case, where nearly all would have suffered from it in infancy. It must be borne in mind that no weight is laid on these numbers, which afford merely an illustration founded upon ratios found to be approximately suitable in 1760, but the considerations involved in it may aid us in understanding how the change in incidence of small-pox during the last 39 years shown in my tables may have originated. In the first place, unless other evidence of an increased virulence in the nature of the disease is forthcoming, we may lay that hypothesis on one side, as not being necessary to explain the peculiarities shown in the tables, while an increasing fatality with advancing years may be a normal feature in the disease. Secondly, I shall take it for granted that vaccination in infancy does not confer an immunity which extends beyond adolescence, and consequently that beyond that age the only safeguard which is general in England against epidemics of small-pox is our improved sanitary condition, which is again modified by the increasing density of population. Judging by the general statistics of disease, we have no reason to believe that our sanitary system is on the high Toad to extinguish any one of our epidemic diseases. We 130 Mr. Gwvtiier on the may, therefore, consider that, as far as adults are considered, the extent to which they are now Hable to attacks of small- pox during an epidemic is approximately expressed by the formula of Bernoulli's first theorem, in which x is now to stand for the number of years during which they have been exposed to small-pox In an epidemic form. If, for instance, a person aged 35 now has passed through a smaller number of years of epidemic than a person aged 35 forty years ago, we may reasonably suppose that his chance of taking small- pox is greater, and that the ratio may be expressed in some way similar to that of Theorem I. As far as infantile small-pox is concerned the law of Incidence Is altered altogether, and I do not know where we are to look for the cause except in our system of vaccination. Much light might be thrown on this subject by a comparison with the similar statistics of the German Empire, if their present system of vaccination has been carried on long enough to give comparable results, and this, I think, must be the case, as it is during the action of the cause that we can but estimate its effect. If, as I have assumed, vaccination has only a protective influence for a limited time, and if its effect is to reduce the number of small-pox cases up to adolescence and then lose its virtue. Its secondary effect must be to leave a larger number subject to small-pox at adult ages, according to Theorem II. And that this effect is operating would seem to be the evidence given by my tables. On this point we may see Bernoulli's answer to certain doctors who objected that Inoculation might form a continuous source of infection, each case communicating the infection to ten others, and these again In the same ratio, thus c^ulckly arriving at a number exceeding the total population of the world. Tlie objection in this form was absurd, but Bernoulli's answer was that perhaps it might be better for the human race if the malady was in this way endemic, and that possibly the Change of Incidence of Small-Pox. 1 3 1 return of an epidemic long delayed might commit more terrible ravages in one year than the uniform endemic disease in a long series of years. This appears to be just the position to which we have arrived, and it is sufficiently grave to demand that all the possible causes should be con- sidered without prejudice or partiality. It is for this reason that I have put forward the argument that, owing to the imperfection of our sanitary and other arrangements, they may carry a certain amount of danger past the age which Bernoulli called the date of civil birth, when a person becomes a useful member of society, and that as the in- creasing death rate from small-pox at adult ages may be the normal consequence of our sanitary position, it becomes necessary to examine that position more closely, and to dis- cover in what way it may be improved. One of the first steps to be taken in the matter ought to be an exhaustive analysis of the action of repeated vaccination now carried out for some years on the death rate in the German empire ; as on this point we have statistics of which one feels the want in investigating the action of inoculation and the earliest effects of vaccination. For instance, when it is claimed, as it was by Mr. Baxendell, that vaccination does not now afford the pro- tection which it did for many years after its general adoption, the obvious answer is that adults were made immune by previous epidemics, and that this acted alongside of vaccina- tion ; whereas now, a vast section of the population have no safeguard other than vaccination. But to weigh this argu- ment we have onl}- the statement from the yearly Bills of Mortality, delivered by Dr. Lettsom to a Committee of the House of Commons in 1802, and its continuation in the Report of the Medical Officer in 1881, which do not show the incidence at different ages. I here wish to maintain that the rise which has been noted in the death rate finds sufficient reason to account for it in the reduction of the 1^2 Mr. Gwyther 07i the general distribution of small-pox. And that, therefore, we must use better sanitary means for dealing with it. The means seem to be three : — 1. Better methods of protecting the individual. 2. Better methodsof preventing the spread of an epidemic. 3. Better methods of preventing the rise of an epidemicr.^ With regard to the latter of these methods, careful search ought to be made to find out whether small-pox is endemic in any localities ; this may possibly be the case without any great small-pox mortality, as it is quite con- ceivable, and not indeed unlikely, that small-pox is not very fatal when the circumstances which favour an epidemic are not present : nor is it necessary that in case of an epidemic it should be most fatal in the locality where it has been endemic. Especially does London deserve a complete examination of this kind, as its death rate from small-pox now maintains itself at sixfold that of the rest of England, as is shown in this table, taken from the Report of the Medical Officer for 1884. Years 1847-49 1850-54 1855-59 1860-64 1865-69 1870-74 .1875-79 1880-84 London... 460 300 ^yi 281 276 654 292 244 34 Provinces . 274 271 192 175 122 389 48 The special circumstances of London seem from this table to have been very favourable to small-pox, as they show no decline comparable with that of the rest of England. In 1886 there was a complete change, there were only 5 deaths in London returned as from small-pox, — i between 20 and 25, 2 between 25 and 35, and 2 between 35 and 45. Nor during the previous term of years was the epidemic without intervals. It is during these periods of quiescence Change of Incidence of Sniall-Pox. 133 that the most effective measures against the epidemic rise of small-pox can be taken, when probably the history of each case could be learnt, and the existence of endemic centres of small-pox, possibly not in a malignant form, could be discovered, and perhaps the circumstances which allow of its existence disclosed. The epidemic of 187 1-2 was European in Its dimensions, and could not be so easily guarded against, but most of our epidemics are more local, and seem to Indicate that some epidemic cause has allowed an existing disease to become malignant. ''a %.'> _ KC*'.' yr 134 Proceedings. MICROSCOPICAL AND NATURAL HISTORY SECTION. Ordinary Meeting, :\Iarch I2th, 1888. The President, Professor W. C. Williamson, F.R.S., in the Chair. Mr. J. J. ASHWORTH was elected a member of the section. Mr. Thos. Rogers showed specimens of a small beetle, Niptus hololeuaiSy which had appeared in large numbers in some dried peppermint. Mr. H. Hyde exhibited a set of plants, collected by Mr. Charles West in Portugal. Mr. John Boyd exhibited by means of the Lantern two sets of drawings. One illustrating the various changes which occur in the development of Argiiliis, the other showing both sexes oi AncJiorella iincinafa. Mr. E. Pyemont Collett exhibited a small type collection of British Heminoptera-Heteroptera. The President showed, under the microscopes, the reproductive gemmules on the roots of mosses, described at the previous meeting. Proceedings. 135 Ordinary Aleetlng, March 20th, 1888. Professor OSBORNE REYNOLDS, M.A., LL.D., F.R.S., in the Chair. Mr. PiCKSTONE, introduced by Mr.W. H. JOHNSON, B.Sc, exhibited and explained the working of a portable pneumatic tool of remarkable power, giving 5,000 to 20,000 strokes per minute, and also a small steam compressed-air engine working at 5,000 revolutions per minute. Mr. Pickstone explained that one of the peculiarities of these inventions was that the piston worked without packing other than the air by which it was cushioned, and he dwelt upon the various uses to which the principle of the inventions might be applied. Ordinary Meeting, April 3rd, 1888. Mr. R. F. GWYTHER, M.A., in the Chair. Mr. Alfred Brothers, F.R.A.S., communicated a paper entitled, " Note on a Nickel Arsenide," by H. E. Brothers, A.I.C, F.C.S. Mr. Brothers said :— In a paper " On the formation of some metallic Arsenides," {Comptes Rendits, Vol. ^G) M. Descamps describes the production of a new Arsenide of Nickel (NigAs or, Ni6As2) by fusing the arsenate first with potassium cyanide and then in boric acid, and also directly by heating nickel oxide at a high tempera- ture with the cyanide in presence of an excess of metallic arsenic. Knowing nothing further of this compound, its 136 Proceedings. formation under different circumstances, and in larger quantities, appears interesting. In the rebuilding of a flue to a furnace in which arsenical nickel-cobalt ores had been smelted, numerous globules of a metal were found intermingled with half-fused brick. An analysis gave : — ' Calculated Found. for NioAs. Nickel 6773%] Co ,. i-26„ Cu I"20„ Fe 0-23,, Arsenic 28-14 „ ^ S 0-45 „ J •70-42% 70-2^ .28-59% 29-8% 99-01 The pieces were dull on the surface, due probably to oxida- tion with a corresponding loss of arsenic. A specific gravity determination at 20° C. gave 8-668. Each globule seems to have contracted considerably on cooling, and has a crystalline structure. Having been left in a damp atmosphere, there formed on the surface small green particles which were insoluble in water but soluble in acids and ammonia. This, I thought, might be the green arsenate formed by direct oxidation, but in the few milli- grammes obtained after several months exposure I did not succeed in detecting arsenic. As to its origin, the ore which had been smelted, and the metal it yielded, contained cobalt and nickel in the pro- portion of one to two. I cannot discover that anything similar has before been noticed after working ores containing much nickel, but it is certain that nothing has ever passed over to the flues from cobalt ores, and this might be inferred from the different behaviour of the two metals in the present case. Proceedings. 137 MATHEMATICAL AND PHYSICAL SECTION. Annual Meeting, March 14th, 1888. Wm. Thomson, F.R.S.Ed., F.C.S., F.I.C, Vice-President of the Section, in the Chair. The Treasurer's accounts for the year 1887-8 were presented. Treasurer's Account. £ s. d. Balance from last year 6 15 o Cash received during present year. . . 2 1 1 1 1 9 6 TI Payments during present year ... 4 4 7 Balance in favour of Section jT^^ 2 4 On the motion of Mr, J. A. Bennion, seconded by Mr. J. Angell, it was resolved : — " That the Treasurer's accounts be received and passed," The following is a list of the members and associates of the Section : — JEembcrs : JOHN ANGELL, F.C.S., F.LC. ALFRED BROTHERS, F.R.A.S. JAMES BOTTOMLEY, D.Sc, B.A, F.C.S. F. J. FARADAY, F.L.S., F.S.S, S. OKELL, F.R.A.S. J. P. JOULE, LL.D., D.CL., F.R,S. WM. THOMSON, F,R.S,Ed., F.C.S,, F.LC. Jl"500dat^ : J. A. BENNION, M.A., F.R.A.S. K 138 PROCEEDINCiS. The following gentlemen were then elected Officers of the Section for the ensuing year : — ■ T. P. JOULE, LL.D., D.C.L., F.R.S. 13ire-}3rc5il)cute:: W. THOMSON, F.R.S. Ed., F.C.S., F.I.C. J. A. 1'>ENNI0N, M.A., Barrister- at-Law. ^xttismzx; : JAMES BOTTOMLEY, D.Sc. B.A., F.C.S. JOHN ANGELL, F.C.S., F.I.C. Dr. BOTTOMLEY made some remarks on a paper by Spring and Van Aubel in the October number of the Anua/es de Chiinic et Physique, on the rate of solution of zinc in hydrochloric, hydrobromic, and hydriodic acids. Mr. Wm. Thomson made some remarks on the subject of the expansion of card and other similar substances under varying conditions of dryness. MATHEMATICAL AND PHYSICAL SECTION. Ordinary Meeting, April nth, 1888. Wm. Thomson, F.R.S.Ed., F.C.S., F.I.C, Vice-President of the Section, in the Chair. Mr. Bennion read a letter from Mrs. Baxendell, acknowledging the receipt of a letter of condolence on the death of her late husband, who was formerly an active member of the Section. Dr. BOTTOMLEY made some remarks on the application of Mendelejeff's Mathematical Method to the determination of the composition of solutions. Mr. Wm. Thomson introduced the subject of the calorific value of carbon as diamond, and as graphite, and as it exists in combination in the gaseous state. Proceedings. 139 MICROSCOPICAL AND NATURAL HISTORY SECTION. Annual Meeting;, April i6th, 1888. Professor W. C. WILLIAMSON, F.R.S., in the Chair. The Hon. Secretary read the Thirtieth Annual Report of the Council of the Section. The meetings have been held regularly each month during the session, and at each of them there has been a fair attendance, the interest being well sustained all through, and although there have not been many important papers read, there has been al\va}^s a number of interesting com- munications made and specimens exhibited. The Council feels that if the advantages offered b}^ the Section were more widely known, it would have the efYect of inducing a large number of naturalists to join the Societ}-. During this session the Section has lost a former Presi- dent and hearty supporter, Mr. JOSEPH Baxendell, F.R.S. He had the faculty, by his tact and kindly manner, of making himself greatly liked and esteemed by all who knew him, and his decease leaves a gap it will be hard to fill. Although for some time before his death he was unable to attend our meetings, he always took a great interest in what was going on at them. Owing to removal from Manchester, inability to attend the meetings, etc., there have been several resignations, but these have been counterbalanced by the addition of new members and associates. It will be seen from the Hon. Treasurer's report that the finances are in a satisfactory condition. To render the ^microscopes more complete, a set of object glasses has been procured. As a full account of the proceedings has been I40 Proceedings. published from month to month, it is not necessary in this report to recapitulate what has been done at the various meetings ; but the Council would point out the ready means of publication which the Society offers, as an inducement to members and associates to communicate original papers. The following is a list of members and associates of the Section : — ^tembcrs. j Dent, Hastings C, F.L.S. Alcock, Thos., M.D.- Ash WORTH, J. J. Bailey, Chas., F.L.S. Barratt, Walter Edward. Barrow, John. Bickham, Spencer H., Junr. Boyd, John. Brogden, Henry, F.G.S. Brown, Alfred, M.D, CoTTAM, Samuel, F.R.A.S. Coward, Edward. Coward, Thomas. CuNLiFFE, Robert Ellis. Dale, John, F.C.S. Darbishire, R. D., B.A., F.G.S. Dawkins, Prof. W. Boyd, M.A. F.R.S., F.G.S. B. Quaritch. D'Orbigny's Dictionnaire d'Histoire Naturell-e, 16 Vols 4 10 o Jno. Boyd, Object Glasses for Microscope 4 14 6 J. E. Cornish, Fowler's Coleoptera, 15 parts .... 3 2 6- Chas. Hargreaves, Postages and Parcels, 19s. 4d., Tea, Coffee, &c., ;^2 2 19 4 Mark Stirrup, Postages (2 Sessions) o 3 o Bank Cheque Book Stamps. 021 Balance in Manchester and Salford Bank (St. Ann Street) 17 8 i Li^ I a 142 Proceedings. On the motion of Mr. C. Bailey, seconded by Mr. J. 'Cosmo Melvill, the report and accounts were adopted. Mr. F. R. Curtis was elected an associate of the section. The following gentlemen were elected officers and members of council for the ensuing session : — $lrcsibcut. J. COSMO MELVILL, M.A., F.L.S. CHARLES BAILEY, F.L.S. ALEX. HODGKINSON, B.Sc, M.B. Prof. W. C. WILLIAMSON, LL.D., F.R.S. %)on. 'Olrciisucei-. MARK STIRRUP, F.G.S. gioiu §aTCtiiri). JOHN BOYD. dLoxuxcii, W. BLACKBURN, F.R.M.S. PETER CAMERON, F.E.S. H. C. CHADWICK. R. E. CUNLIFFE. R. D. DARBLSHIRE, B.A.,F.G.S. F. NICHOLSON, F.Z.S. THOMAS ROGERS. THEODORE SINGTON. Mr. P. Cameron, F.E.S., exhibited specimens of spiders and ants to show mimicr}% also Arenetra pilosella, Grav., a genus and species of IcJincmnonidce new to the British fauna. It was taken on Ben Lawers at Easter last year, on the snow, at an elevation of over 2,500 feet. Mr. H. C. Chadwick showed under the microscopes specimens of a new species of parasitic Copepoda LicJio- molgiis sabellcEy discovered by him August, 1887, clinging by means of its peculiarly modified posterior antennae to the branchial filaments of Sabclla penicillus, a tubicolous annelid found in great abundance on the beach at Beaumaris. Mr. P. Cameron, 1\E.S., read a paper entitled " Descrip- tions of twenty- three new species of Hymenoptera." Mr. J. Cosmo Melvill, M.A., F.L.S., exhibited his collection of Cyprcea^ and read a paper entitled "A survey of the genus Cypra^a (Linn.), its Nomenclature, Geographical District, and Distinctive Affinities ; with descriptions of two new species, and several varieties." Proceedings. 143 Annual General Meeting, April 17th, 1888. Professor OsBORNE REYNOLDS, LL.D., F.R.S., in the Chair. Mr. E. Leader Williams, jM.I.C.E., and Mr. James Arthur Hutton, of Manchester, were elected ordinary members of the Society. The following gentlemen were elected honorary mem- bers of the Society : — Professor F. ZiRKEL, University of Leipsic ; Professor GUSTAVE Dewalque, University of Liege ; Professor JOHANN WiLHELM HiTTORF, Poly- technicum, Munster ; Professor S. CannizzarO, University of Rome. The annual report of the Council was presented. Annual Report of the Council, April, 1888. The annual balance sheets, prepared by the Treasurer, show that the finances of the Society are in a less straitened condition than they were a year ago, the debit balance of the General Account of ^195. i6s. 8d. having been reduced to ;^2i. 5s. 4d. on the 31st March, 1888, at which date the funds in hand amounted to i^2i8. 5s. yd. The sources of income are set forth in the accompanying statement, where they are compared with the figures of the previous year. The Societies which now make use of the premises are the Manchester Geological Society, the Man- chester Medical Society, the Manchester Photographic Society, and the Manchester Scientific Students' Associa- tion. The Manchester Microscopical Society has removed to other quarters. 144 Proceedings. As regards the credit side of the account, full details of the items constituting the ordinary expenditure were given in the reports of the two preceding years, and it is necessary to allude here only to those which indicate any important change. In Charges 2ipoii Property is a small item for the cost of affixing tablets of names to the portraits of distinguished men which hang upon our walls, and of the marble busts in the possession of the Society. House Expenditure. — During the Meeting of the British Association in Manchester last autumn, the Society's rooms were thrown open to the members of the Association, and the Society was honoured by the presence of many of its foreign honorary members. In this connection your Council has gratefully to acknowledge the liberality of the Local Committee of the British Association in making a prospective grant to the Society of the moiety of any surplus funds subscribed to meet the expenses of the Manchester meeting, and also the present of the handsome Library desk which stands in the Natural History Room, " in recognition of services rendered by the Society." In Administrative Charges y the salary of the Curator and Assistant Secretary terminated at the quarter ending 30th June, 1887, after which date your Council decided to abolish the office. In the last report it was stated that the Society's respected housekeeper and collector, Mr. William Roscoe, had felt obliged, through failing health, to tender his resignation, but at the request of the officers, he continued to discharge the duties of his post until the conclusion of the meeting of the British Association. Upon the occasion of his leaving, the President, on behalf of the members,, presented Mr. Roscoe with a purse containing £40, in recognition of his faithful services, accompanied by an expression of regard engrossed on vellum. In November last, your Council appointed as clerk and housekeeper^ Proceedings. 145, Mr. Charles Hargreaves, at a slightly higher salary than was paid to his predecessor ; but advantage was taken of the opportunity to make some changes in the duties of the office in respect to clerical work, such as entering daily the donations to the Library, recording the publications received from Societies under their respective names, &c. The Council at the same time discontinued the additional remu- neration for attendance on Sections and Societies formerly paid, preferring to make the salary offered an inclusive one for all the duties required. In the Publishing Account^ as compared with the previous- year, there is a considerable diminution in the expenditure, due to several causes, some of which were alluded to in last year's report. The chief economy lies in the alteration in the form of publication of the papers read before the Society, as particularised in the previous report, and your Council has reason to believe that the change is acceptable to the members, as leading to a more rapid and regular publication, and in the improved typography and paper of the new issue. Soon after the new and consolidated form of publication had been resolved upon, the Council learned with extreme regret of the death of the editor of the Society's publications, their old and valued friend Mr. Joseph Baxendell, F.R.S. At the earnest request of his colleagues, one of the Society's secretaries, Mr. Frederick James Fara- day, F.L.S., accepted the post of honorary editor, and his duties commenced with the first number of the 4th series of the Society's Memoirs and Proceedings. Mr. Alfred Brothers, F.R.A.S., during the Session \Z'S>6-'j, had presented to the Council an index which he had made of the Society's Memoirs, 2nd Series, Vols. XIII. to XV., and 3rd Series, Vols. I. to X. The consideration of this index has led your Council to arrange for the preparation and publication of an index of the whole of the volumes of Proceedings and Memoirs of the Society since its 146 Proceedings. foundation, and in the preparation of such index the work of Mr. Brothers will be utilized. It will be noticed from the summary of the accounts which follows the balance sheet, that the Fire Account has been closed by the balance of £60. 12s. 7d., which remained at the credit of that account last year, being transferred to the General Account of the Society. The Hon. Librarian reports that the number of books, pamphlets, and part volumes received is about the same as last year. Nothing has been spent on binding, but it is hoped that the funds of the Society will allow of a grant being made for this most urgent and necessary purpose during the coming year, to supplement the ^34. i8s. 2d which remains at the credit of the Binding Fund. The Council considers it desirable to continue the system of electing sectional Associates, and the usual resolution will be submitted for the approval of the members at the Annual General Meeting. The number of members on the roll on the 31st March, 1888, was 130, or 6 less than at the corresponding date last year. 7 new members have been elected during the Session ; 10 have resigned ; and 3 have died ; viz., Mr. Joseph Baxen- dell, F.R.S., F.R.A.S., Professor Balfour Stewart, LL.D., F.R.S., and Mr. Charles Moseley. An elaborate memoir of Mr. Baxendell, prepared at the special request of the Council by Dr. James Bottomley, B.A., F.C.S., was read before the members, and will be found in the present volume of Memoirs and Proceedings. To the record of Mr. Baxendell's life and work therein given, the Council has only to add an expression of its sense of the stimulating influence which Mr. Baxendell exercised in connection with the work of the Society. He will be remembered by his colleagues and the members generally, not merely for the value of his official services and the high importance of his own contributions to science, Proceedings. 147 but for the keen and encouraging interest which, up to the end of his long Hfe, he uniformly manifested in the work of the younger members, even when it lay outside his own special lines of research. The Council has keenly felt the heavy loss sustained by the Society in the death of Professor BALFOUR Stewart, only a few weeks after the opening of the session of his first year as President. Professor Arthur Schuster, Ph.D., F.R.S., at the request of his colleagues, has undertaken to prepare an account of Dr. Stewart's life and work, which will appear as a memoir in the volume of Memoirs and Proceedings for the session now closing. Mr. Charles Moseley was elected a member of the Society only near the end of the session \'^'$>6-y^ and as his death occurred before the opening of the subsequent session, his connection with the Society was of very brief duration. During the interval, however, he gave evidence of his warm sympathy with its objects by the prominent part he took in the work of entertaining the British Association during its third visit to Manchester. Mr. Moseley was born in Manchester in 1839, ^^^^^ died at his residence, Grangethorpe, Rusholme, October ist, 1887. He was remarkable for kindness and affability, combined with extraordinary energy. The earlier part of his career was devoted to the development of his business as an india- rubber manufacturer, at the Chapelfield Works. His first appearance in public life was on his acceptance of the office of Chairman of the Manchester Aquarium Company, with the hope of rescuing that institution from its embarrassments. During this period he gave a cordial, appreciative, and enterprising support to every attempt to maintain the Aquarium as a place of educational recreation and scientific study for the people of Manchester. The writer of this notice was closely associated with Mr. Moseley in the efforts then made, and remembers with peculiar pleasure his frank 148 Proceedings. and unflagging co-operation. These efforts proved futile. The closing of the Aquarium about coincided with the appearance of Professor Graham Bell with his telephone, at the Plymouth meeting of the British Association in 1877. Mr. Moseley was one of the first to realise the commercial importance of the discovery, and immediately set to work to introduce it in this part of the country. The writer witnessed his first trials with the instrument at the Chapelfield Works, and well remembers the enthusiasm and confidence with which he spoke of its future. Later on, as Chairman of the Lancashire and Cheshire Telephone Company, Mr. Moseley carried on with singular energy and ability a contest with the Post Office in order to promote the development of long-distance telephoning, which the Government endeavoured, under the Telegraphs Act, to prevent. As a result of Mr. Moseley's severe labours and frequent interviews with the Postmaster-General (Mr. Fawcett) the " trunk-line " system, by which it is possible for most of the Lancashire towns to hold communication with each other, was established. He also took a strong interest in the development of electric lighting. He was a Director of the Edison Electric Light Com- pany, and his own residence was lighted throughout by electricity. Mr. Moseley was a leading member of the Consultative Committee formed to prepare an independent report on the Manchester Ship Canal project after the failure of the first attempt to raise the capital, and was conspicu- ously influential in connection with the subsequent successful launching of the enterprise. As Chairman of the Music, Electric Lighting, Refreshments, and Gardens Committee of the Manchester Jubilee Exibition, Mr. Moseley con- tributed powerfully to the extraordinary success of that memorable undertaking. Few men have compressed so much and such important public work within the short space of about ten years, and there can be no doubt that Proceedings. 149 had his life been spared he would have proved a valuable and earnest friend of the Society. Death has also removed the following Honorary Mem- bers from the Society's roll, viz. : — Mr. J. B. Dancer, F.R.A.S., Professor A. de Bary, and Professor Asa Gray. Memorial notices of the two last-named by Mr. Charles Bailey, F.L.S., have already been published in the present volume of Memoirs and Proceedings. In consideration of Mr. Dancer's long connection with the Society it is fitting that a more ■detailed record of his life and work should also be included. John Benjamin Dancer was born in London on October 8, 18 12, and may be said to have been born an optician, his father and grandfather having been makers of optical and scientific instruments. In 18 18 his father, Mr. Josiah Dancer, removed to Liverpool, where he carried on the business of optician and philosophical instrument maker ; he was also a public lecturer on science, and was an active promoter of the Mechanics' Institute and Literary and Philosophical Institution of Liverpool. The foundation of Mr. Dancer's optical knowledge was laid in his father's workshop. He also assisted his father in his lectures, and very early in life evinced a strong bias for mechanical and scientific pursuits. In 1835 the father died, and the business was afterwards carried on by the subject of this sketch. After a few years Mr. Dancer removed to Manchester, where, in 1842, he was elected a member of this Society, of which he was in 1884 elected an honorary member. In 1845 he became a Fellow of the Royal Astronomical Society. In the successful exhibitions which were held many years ago at the Mechanics' Institution, both in Cooper Street and afterwards in David Street, Mr. Dancer took a very important part. It was he who suggested the appli- cation of photography to the magic lantern, and who, by 1 50 Proceedings. the use of the Hme-Hght, or Drummond h'ght, as it was then called, made such application possible. The exhibition of photography on so colossal a scale took the world by surprise, and this grand application of the marvellous art, which has now become so familiar, was received with the admiration it deserved. Mr. Dancer's services to the lantern did not end with the application of photography to it ; he also improved the arrangement of the optical parts^ producing a clearer image and a flatter field than had before been obtained. At the Mechanics' Institution Exhibitions Mr. Dancer was in no small measure responsible for the '' fairy fountain," or, as it was first called, the " optical chro- matic fountain." The fairy fountain of the Jubilee Exhition of 1887 was an extension of the original idea, and though' shown on a much grander scale and in the open air, did not excel the beauty of the original Mechanics' Institution fountain. A complete list of the instruments, apparatus, and processes in the invention or improvement of which Mr. Dancer was concerned is too considerable to reproduce here. In 1838 he suggested the introduction of earthenware porous jars to separate the two solutions used in voltaic batteries, which before this time was effected by means of bladder or other animal tissue. Porous jars have since been universally used. Dr. Golding Bird, in his " Elements of Natural Philosophy," published in 1839, gave Mr. Dancer credit for the invention of the porous jar ; but that is the most conspicuous acknowledgment he received for an improvement of the very greatest importance to science. In the same year he invented a still more important instrument, namely, the automatic contact breaker, or the vibrating interrupter — an instrument of universal application at the present day wherever electricity is employed for telegraphy or signalling. Again, in 1838, and resulting from the same experiments, came the deposition of metallic Proceedings. i 5 1 copper by voltaic electricity. This was the beg-inning of electro-plating, of which art Mr. Dancer was really the inventor, though others have taken the credit of it. Among other improvements of batteries made by Mr. Dancer there was the introduction of crimped or corrugated plates, so as to give a larger acting surface — a device which has been the subject of recent patents by some who know nothing of Mr. Dancer's having forestalled them by half a century. In 1839 he introduced photography to Liverpool, working Daguerre's process, and in 1841 he was the first to do the same for Manchester, which had not yet seen a photographic camera. In the same year he commenced microscopic photography on Daguerrotype plates, and this wonderful art he perfected in 1852, when the introduction of the collo- dion process much simplified this and every other photo- graphic process. These tiny examples of photography excited the warmest admiration and commendation of Sir David Brewster and other distinguished men. Mr. Dancer's diffidence prevented him from claiming for himself in this as in other discoveries the acknowledgment that was his due. The invention of micro-photographs was claimed elsewhere, but after a full inquiry by Mr. Joseph Sidebotham, Mr. Edward W. Binney, and the Manchester Photographic Society, Mr. Dancer's claim was allowed. In his record Mr. Sidebotham wrote in 1859 : " Mr. Dancer's modesty will not allow him to speak of his own discoveries, but I am sure you all join in the annoyance I have felt in seeing persons coolly claim as their own nezv discoveries what our respected townsman has accomplished so many years ago." In 1853 Mr. Dancer invented the twin-lens stereoscopic camera ; that is, a camera with two lenses placed side by side, at a short distance apart. Before Mr. Dancer took the matter in hand photographs for the stereoscope were taken with a single camera, which was moved for the second picture, and operators could not agree as to the proper amount of 152 Proceedings. movement ; some advocated eight inches, and some so much as twenty-four. Mr. Dancer was convinced that the proper separation was the ordinary distance between the eyes of a human being, and made his camera under this idea ; from that time no other form of camera has been used. Omitting several other instruments which Mr. Dancer improved, mention must be made of his connection with Dr. Joule in his heat experiments and discoveries. Dr. Joule found the necessity for accurate thermometers, and with Mr. Dancer's assistance determined to make them for himself The result was the production of a new thermometer, the first made in England with any preten- tions to accuracy. Mr. Dancer arranged the apparatus for measuring the internal capacity of the bore of the thermometer tubes, and constructed for Dr. Joule the apparatus which he employed in his determination of the mechanical equivalent of heat, also a tangent galvanometer and other original instruments. When Mr. Dancer established himself as an optician in Manchester, his presence soon made itself felt amongst the few microscopists then living in the district. Good micro- scopes were then costly, and worthless ones very common. Mr. Dancer successively brought out several forms of in- struments, as excellent in their mechanical and optical arrangements as they were moderate in price. Instruments fully equal to the requirements of original research were thus brought within the reach of many whose observing faculties were more conspicuous than their financial resources. It would be difficult to over-estimate the stimulus which Mr. Dancer thus gave to Manchester micro- scopy ; it cannot be doubted that the present energy of our local microscopists is the direct outcome of the impulse which their means of research then received. Latterly Mr. Dancer lost his most precious possession — Proceedings. 153 his eyesight — not suddenly, but by degrees. In spite of this, his active mind never lost its interest in the studies and discoveries of his earlier years. By his numerous friends his society was to the last highly appreciated, and his modest and kindly disposition greatly enhanced the pleasure and advantage of his conversation. His single- minded devotion to every branch of physics was not less remarkable than his unfailing industry and the inventive genius by which it was directed to results of no ordinary importance to the mechanician and the lover of natural science. He died at his residence, Greenhill Street, Green- heys, on November 24th, 1887. The following papers and communications have been read at the ordinary meetings of the Society during the past session, or will be read this evening : — October i8th, 1887. "On the possible equations expressing the decomposition of Potassic Chlorate by Heat," by James Bottomley, D.Sc, B.A., F.C.S. November ist, 1887. "Pasteur and Faraday: Note on Dr. Tyndall's Introduction to the Eng- lish Edition of the 'Histoire d'un Savant par un Ignorant','' by F. J. Faraday, F.L.S. November 15th, 1887. "On the Electrical Attraction of Quartz and the unsuitability of this sub- stance as a protecting medium for compasses, watches, etc.," by Alex. Hodgkinson, M.B., B.Sc. November 29th, 1887. "The effect of the small variation of the density of the atmosphere on the amplitude of plane waves of Sound approaching the earth," by Ralph Holmes, B.A. December 13th, 1887. "Memoir of the late Joseph Baxendell, F.R.S., F.R.A.S.," by James Bottomley, D.Sc. December 27th, 1887. "Note on the Bi-centenary of the Frma'p'a," by James Smith. January loth, 1888. "An application of Huyghens' Principle to a spherical wave of light," by R. F. Gwyther, M.A. L 154 Proceedings. jAiNUARY 17th, 1888. Correction to "On the Composition of projections in geometry of two- dimensions," by James Bottomley, D.Sc. (See Vol. X,, 3rd Series, Memoirs). January 24th, 1S88. "An additional Note on the equations expressing the decomposition of Potassic Chlorate by heat," by James Bottomley, D.Sc. "On the Union of Hydrogen and Nitrogen," by Prof. II. B. Dixon,. M.A., F.R.S. February 7th, 1888. "Notice of Dr. A. de Bary and Dr. Asa Gray," by Charles Bailey, F.L.S. ; "Notice of the late Dr. J. T. Boswell," by Charles Bailey,. F.L.S. "Note on an erratic block observed during excavations for a sewer in Oxford Street, Manchester," by Percy F. Kendall, Assistant Lecturer on Geology at the Owens College, Manchester. Communicated by Thomas Kay. February 14th, 1888. "Notes on a small collection of Mosses from Mauritius," by J. Cosmo Melvill, M.A., F.L.S. February 21st, 1888. "On the change of incidence of Small-Pox at different ages during the years 1848-86." Part I. By R. F. Gwyther, M.A. "A method of calculating the Electrostatic Capacity of a Conductor."" By Henry Holden, B.Sc, Bishop Berkeley Fellow in Physics at the Owens College, Manchester. Communicated by Prof. A. Schuster, Ph.D., F.R.S. March 6th, 1888. "On the change of incidence of Small-Pox at different ages." Part II. By R. F. Gwyther, M.A. April 3rd, 1888. "Note on a Nickel Arsenide." By H. E. Brothers, A.I.C., F.C.S. Communicated by Alfred Brothers, F.R.A.S. April 17th, 1888. "A Survey of the genus Cypriva (Linn.), its Nomenclature, Geographical District, and Distinctive Affinities; with . descri]ilions of two new species and several varieties." By J. Cosmo Melvill, M.A., F.L.S. "Descriptions of twenty-three new species of Ilymenoptera." By I*. Cameron. Communicated by Charles Bailey, F.L.S. "Memoir of the late Professor Balfour Stewart, LL.D., F.R.S." By Prof. A. Schuster, Ph.D., F. R.S., F.R.A.S. It was moved by Mr. Hany Grimshaw, F.C.S. , seconded by Mr. John Bell Millar, B.E., and resolved, "That the Annual Report be adopted and printed in the Society's Memoirs and Proceedings^ Proceedings. 155 It was moved by Dr. A. Hodgkinson, B.Sc, seconded by Mr. William Thomson, F.R.S.E., F.C.S., and resolved : — " That the system of electing Sectional Associates be con- tinued during the ensuing session." On Professor Schuster expressing a wish to be relieved of the duties as one of the Society's Secretaries, it was moved by Dr. James Bottomley, B.A., F.C.S., seconded by Mr. Charles Bailey, F.L.S., and resolved : — " That the thanks of the Society be presented to Dr. Schuster for his past services." The following gentlemen were elected Officers of the Society and Members of the Council for the ensuing year : — OSBORNE REYNOLDS, M.A., LL.D., F.R.S. "^Bia-JPresii^entsi. WILLIAM CRAWFORD WILLIAMSON, LL.D., F.R.S., Foreign Member of the Royal Swedish Acad. Sc. Sir henry ENFIELD ROSCOE, B.A., LL.D., D.C.L., F.R.S., F.C.S., M.P. JAMES PRESCOTT JOULE, D.C.L., LL.D., F.R.S., F.C.S., Corr. Mem. Inst. Fr. (Acad. Sc.) Paris, and Roy. Acad. Sc. Turin. ARTHUR SCHUSTER, Ph.D., F.R.S., F.R.A.S. FREDERICK JAMES FARADAY, F.L.S., F.S.S. REGINALD F. GWYTHER, M.A. treasurer. CHARLES BAILEY, F.L.S. librarian. FRANCIS NICHOLSON, F.Z.S. ©tker JEemb^rs ot thz Council. J AS. BOTTOMLEY, B.A., D.Sc, F.C.S. JOHN BOYD. HAROLD B. DIXON, M.A., F.R.S. WILLIAM HENRY JOHNSON, B.Sc. JAMES COSMO MELVILL, M.A., F.L.S. S. B. WORTHINGTON, C.E. MANCHESTER LITERARY AND Chai-h's Bailey, Treasurer, in Account zuith the Society, H)r. Statement of the Accounts 1887-8. 1886-7. 1888— March 31st:— ^ s. d. ;^ s. d. ^ s. d. 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Stock .. .. 59 8 o 59 4 2 To Bank Interest, less Bank Postages, 1887-8 ©77 2 13 5 To Centenary Fund, 1886-7 •• •• •• •• 22 10 4 To Binding Fund, 1887-8 :— Donations, as per detailed list on page 152 " Proceedings" 1886-7 •• 31 5 o 42 7 o To Fire Account, 1886-7 •• •• ^45 9 3 ;Cso3 5 " ;C895 12 6 1888. — April I. To Cash in Manchester and .Salford Bank, Limited .. l'l^^ S 7 PHILOSOPHICAL SOCIETY. from 1st A^ril, 1887, to the T,ist March, 1888, with a Comparative for the Session 1886- 1887. (Jr. I8B7-B. ia86-7. 1888.— March 31st :— £ s. d. £ s. d. ^ s. d. £ s. d. 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Audited and found correct, (Signed) JOHN ANGELL, ALEXANDER HODGKINSON. 158 Compounders' Fund : — Balance ist April, 1887 Compounding Fee— Mr. Charles Lowe . , Balance in favour of this Account, 31st March, lE Natural History Fund : — Balance in favour of this Account, ist April, 1887 Dividends received during the Session 1887-8 . . Expenditure during the Session lE ;^ s. d. £ s. d. [25 o o 26 5 o 7 17 6 59 8 o 67 5 6 13 17 9 53 7 9 Balance in favour of this Account, 31st March, 18S8 Binding Fund : — Balance in favour of this Account, ist April, 1S87 - 13 2 Donations received during the Session 1887-8 ^^ ^ Balance in favour of this Account, 31st March, 1888 34 18 2 General Account :— ^39 10 11 Balance against this Account, ist April, 1887 ^19516 8 Expenditure during the Session 1887-8 27127 466 19 3 Transfer from Fire Account, 1st April, 1887 6012 Receipts during the Session 1887-8 385 i 4 445 13 II Balance against this Account, 31st March, 1888 21 s 4 Cash in Manchester and Salford Bank Limited, 31st March, 1SS8 ^218 5 7 Hynienoptera. 1 59 Ordinary Meeting, April 17th, 1888. Professor OsBORNE REYNOLDS, LL.D., F.R.S., in the Chair. Mr. Charles Bailey, F.L.S., communicated a paper 'entitled " Descriptions of twenty-three new Species of Hymenoptera," by P. Cameron. Mr. J. Cosmo Melvill, M.A., F.L.S., communicated a paper entitled " A Survey of the genus Cypraea (Linn.), its Nomenclature, Geographical District, and Distinctive Affinities ; with descriptions of two new Species and several varieties." Professor A. SCHUSTER, F.R.S., read a paper entitled " Memoir of the late Professor Balfour Stewart, LL.D., F.R.S." Descriptions of twenty-three new species of Hymen- optera. By P. Cameron. Communicated by Chas. Bailey, F.L.S. (Received April lyt/i, 1S88.) The chief interest of the following paper consists in its containing either descriptions of species belonging to genera or groups which have been very little studied, and which consequently are very little known ; or descriptions of species of well-known genera from regions which have been hardly explored, at least as regards their Hymenop- terous Fauna. Of the former class I may allude to the six new species oiEpyris, of which three are European, including one from England, and to the six new parasitic Cynipidae from Britain. Possibly the most important species described i6o Mr. Camp:ron on is the new species of Ainpulex from Gibraltar, there having been only one European species described, the genus itself, too, being a remarkable one, and more representative of tropical than of temperate regions. I have to express my indebtedness to Mr. J. J. Walker, R.N., for a small, but highly interesting, collection of Hymenoptera from Gibraltar ; to Mr. J. Helms, of Grey- mouth, New Zealand, for an equally interesting collection from his district, and to Mr. J. Cosmo Melvill for the curious Bracon from Bogota. ^ I may be allowed to make here some observations on the question of the multiplication of "genera" in the Hymenoptera, as it appears to me that the creation of so many so-called "genera" may lead not only to confusion, but may be even positively injurious to the progress of the study of the Hymenoptera. The late Prof Arnold Foerster is the author who initiated the principle of minute analytical analysis in splitting up the old genera. That some of these genera may have been rather too widely defined may be granted ; but it does not follow that Foerster's system was an improvement. If genera are to be formed, they should be defined, not as regards the German species, but as regards the species from all parts of the world. Once commence to define genera from one or possibly two characters and you then find yourself logically bound to the creation of an endless number of genera. The objections to most of the genera carried out on the Foersterian lines are that they do not apply to exotic species, and further, that in many cases the characters employed to define the genera are found to be specific rather than generic when traced through a series of species from all parts of the world. In working out the parasitic Hymenoptera for the "BiologlaCentrall- Americana," I endeavoured to arrange the species according to Foerster's Hyinenoptera. i6i " genera," but I soon found out that it was impossible to do so — that in fact the species could not be referred to them ; and that if Foerster's method was to be followed, the erection of a large number of "genera " must be attempted. There are, however, serious objections to that being done, with our present limited knowledge of exotic forms ; not only so, but many of the characters employed by Foerster and his followers merge so much into one another that they are perfectly useless for purposes of generic diagnosis, e.g. the abdominal segments in Piniplides. Even as regards Euro- pean species the method in many cases fails. Take, for example, Foerster's divisions of Kleditoma. Of these he has five, arranged according to the number of joints in the antennal club. If species were to be discovered with two- and one-jointed clubs,"genera" would logically have to be erected for them ; more than that the species I have described in this paper under the name of Kleditoma melanopoda should form the type of a " genus," because it has no antennal club at all. Then again, the males of all these divisions have no distinctive characters ; so that the " genera " are founded exclusively on the females. As another example of the multiplication of genera, I may allude to the recent elevation by Herr Konow of some of the divisions of Stronglogaster and Blemiocauipa to generic rank. If these are to be accepted, a large number of genera must be formed for the American species ; and I question very much if the characters employed by Herr Konow will not be found on examination to merge so much into one another as to be incapable of rigid definition. That all large genera fall into well marked groups is, of course, true; and in monographic works such groups should be defined; but it is questionable if anything is to be gained by giving them names. The naming of the species oi Blennocampa (using the word in the Thomsonian sense), for example, is not greatly facilitated by certain of the groups being separated from it and given names. 1 62 Mr. Cameron 071 The truth seems to be that the species of the larger genera arrange themselves differently in the various zoo- logical regions. To carry out the present system of minute generic analysis can only lead to the creation of "genera," the characters of which are only applicable to the species of one region. With our present knowledge of the Hy- menoptera, the system, to my mind, when carried to extremes, will do more harm than good, and may lead to great confusion; for it will render the identification of genera almost impossible when species are studied outside the limits of the region where such genera have been formed. Possibly in no order of insects is the question of generic definition more perplexing than in the Hymen- optera; the greater the reason, therefore, is there for care being exercised in the formation of new genera ; as, unless this is done, it will simply lead to confusion and additions being made to an already too large synonymy. TENTHREDINID^. SeLANDRIA (?) ROTHNEYI, Sp. IIOV. Nigra-coerulea ; coxis, trochantcribits posticis diinidioque basal I tibiariun posticariini^ a Ibis ; a I is fere Jiyalinis. Long. 7 mm. Hab. Barrackpore, Bengal {G. A. J. RotJiney). Antennae shortly pilose, longer than the head and thorax united, the third joint slender, slightly curved, nearly one-fourth longer than the fourth ; the 5th — 8th joints produced sharply at the apices beneath ; the 6th — 8th much shorter than the fifth. Head : the face and clypeus covered with long white hair ; clypeus truncated at apex ; frontal area distinct, obscurely roughened ; a short keel in the centre, which is depressed ; sutures on vertex not reaching to the back of the head ; eyes converging in front, reaching near to the back of the head. Body and legs shortly and Hynienoptera. 163 .sparsely covered with white pubescence ; cenchri large, white ; calcari about one-fourth of the length of the meta- tarsus ; claws bifid. Second marginal cellule a little longer than the first ; first transverse cubital nervure absent ; transverse basal nervure received beyond the middle of the cellule ; the second recurrent nerv^ure is received about the same distance from the second transverse cubital nervure that the transverse radial is from the second transverse cubital. If the first transverse cubital nervure were not absent this species agrees in neuration \\-ith Selandria. With the material at my disposal it is impossible for me to say if the absence of this nervure is normal ; and I therefore leave the species in Selandria. If there are species similar to the species here described, it might be referred to Aneitgrnenics, but that I suspect was found on a Selandria which had the first transverse cubital nervure faint or absent ; and, there- fore, I am inclined to regard Aneiignienus as synonymous with Selandria (cf. Cameron, Mon. Brit. Hym. I. p. 264.) Emphytus AZTECUS, sp. nov. Niger^ fusco piibescens ; labro, palpis, tegiclis^ linea pro- noti, coxis, trochanteribiLs, basi et apice feniornni^ tibiis tarsisqne anterioribiis, alb is ; alls fusco hyalijiis. $ Long. 5 mm. Hab. Mexico, Orizaba, December (F. D. Godman and H. H. Smith). Antennas densely, but shortly, pilose; the third joint •considerably longer than fourth. Head finely punctured; frontal area and vertical sutures indistinct; apex of clypeus transverse. Thorax shining; impunctate; cenchri large, white. Abdomen considerably longer than the head and thorax united. Transverse basal nervure received near the middle of the cellule ; the second recurrent nervure a little -before the middle. 1 64 Mr. Cameron on EmpJiyUis improbns Cresson is the nearest relative known of this species ; hnprobus may be known from it by having the third, fourth, and fifth joints of the antennae of nearly equal length ; by the abdomen being " about as long as the head and thorax"; in the metatarsus being as long as all the other joints united, &c. E. mexicamis (Cam.) has only the knees and fore-tibiae white. CYNIPID^. Onychia striolata, sp.nov. Nigra; capite et tJioimce sUdolatis^ breviter pilosis ; tibiis tarsisque ante7'ioribiis,piceis ; flagello anteitnariun subtusfiisco; alis nyalinisy nervis pallida testaceis. $ . Long, fere 4 mm. Jlab. Barrackpore, Bengal (G. A. J. Rothney). Antennae longer than the body, of nearly uniform thickness ; the third and fourth joints subequal. Head and thorax opaque, covered with a short whitish pubescence. Head rugosely punctured, striolated on the vertex and behind the eyes ; front slightly depressed, finely rugose ; a straight keel runs down from the direction of each ocellus ; . mandibles piceous. Sides of pronotum coarsely striolated ; the top a little depressed, finely rugose, this central part being distinctly separated from the striolated sides. Meso- notum coarsely rugose ; parapsidal furrows wide, distinct ; the space between the keels at the base crenulated ; mesopleurae shining, impunctated ; excavated in the centre. Scutellum channelled ; keeled down the centre ; the foveae at the base shining, impunctate ; the sides whitish ; the apical part with stout transverse keels ; the apex almost transverse. Central part of metanotum shining, impunctate; separated by stout keels from the reticulated, densely pilose sides. Abdomen shining ; the apical half of the petiole striolated above. The anterior legs shortly and sparsely covered with white hair ; the posterior densely ; the posterior Hymenoptera. 165 tibiiu and femora opaque, absoletely punctured ; the tibiae channelled. A larger species than O. Westzvoodi, Dbm. differing from it otherwise in the front not being rugosely punctured and bearing three distinct longitudinal keels, the lateral keels, too, projecting more ; in the sides of the pronotum being more strongly striolated ; in the tegulse being black, and the nervures whitish ; and in the abdomen being longer, the petiole especially being as long as the hind coxae, while in O. Westwoodi it is not half the length. As bearing on the distribution of OnycJda^ I may remark that Mr. J. J. Walker, R.N., has taken O. notata, Fonsc, at Benzus Bay, Morocco. KlEDITOMA NIGRIPES, Sp. 710V. Nigra, gcnicidis tibiisqite piceis, alls hyalmis, nervis piccis, antennis thorace longioribus, clava yartiailata, abriipta. % Long. 2*3 mm. Hah. Dulwich {T. R. Bilhcps.) Black ; knees and base of tarsi piceous ; wings hyaline; nervures piceous-black. Antennae longer than the head and thorax united ; the third joint attennuate at the base, twice the length of the fourth, the fourth and fifth joints narrowed at the base, longer than broad ; joints 6 — 10 moniliform, as broad as long ; joint 1 1 distinctly thicker than the tenth, but shorter and thinner than the thirteenth, the three forming a well-marked club. Occiput striated. Sides of scutellum longitudinally striated ; the discal fovea small, shallow, indistinct ; apex of the scutellum below the cup forming a curved hook-shaped projection. Metanotum aciculate, depressed at the base, abdomen scarcely as long as the head and thorax united ; the hair fringe thick, large, griseous. Radial cellule open at base and apex ; the second -abscissa of radius three-fourths of the length of the third. This is the largest species of the section of Kleditoma 1 66 Mr. Cameron on with a 3-jointed club, and with the apex of scutellum pro- longed into a sort of beak { = Rhyjichacis, Foerster). It is- most nearly related to K. nigra, but the much darker legs and wing nervurcs ; the striated occiput, the more elongated radial cellule, which is widely open at base and apex, and the sharper beak-shaped apex of scutellum sufficiently distinguish it from the smaller nigra. KLEDITOMA CRASSICLAVA, sp. nov. Black, shining ; the knees and tarsi piceous ; wings yellowish-hyaline, the nervures piceous ; abdominal hair- fringe whitish. Antennse nearly as long as the head and thorax united ; the 3-jointed club stout, thick ; its basal joint distinctly shorter and narrower that the 12th. Apical margin of wing obtusely rounded, but very slightly incised. Apex of scutellum prolonged into a beak. Length 2 mm. Hab. Bonar Bridge, Sutherlandshire. {Cameron.) May be known from K. nigra by being larger and stouter, by the stouter antennal club, by the blacker legs,, and by the apical margin of the wings being hardly incised. Kleditoma CALEDONICA, Sp. nov. Black, shining ; the four anterior knees, tibiae and tarsi, testaceous, the posterior and the trochanters piceous ; wings hyaline, the nervaires testaceous ; the abdominal hair fringe griscous. Antcnn^u longer than the head and thorax united ; the flagellum before the club slender ; the 3-jointed club distinct, the joints conical, distinctly attenuated at base and apex ; the nth joint per- ceptibly shorter than the 1 2th. Radial cellule elongated; the second abscissa of radius fully one-fourth longer than the first ; apical margin obtusely incised. Apex of scutellum not beak-shaped. Length i mm. A smaller species than K. striaticollis, and easily known Hyvieiioptcra. 167' from it by the joints of the club being narrowed at base and apex and clearly separated. Hab. Claddich, Loch Awe {Camero'fi). Kleditoma STRIATICOLLIS, sp. nov. Black, shining, the knees broadly, trochanters, base of femora, and tibiae and tarsi, piceous; wings clear hyaline, the nervures testaceous. Antennae as long as the head and thorax united; the three-jointed club abrupt; its joints of equal thickness ; the basal a little shorter than the second ; the ninth and tenth joints are thicker than the preceding and more globular. Radial cellule elongate; the second abscissa of radius perceptibly longer than the first; apical margin of wings obtusely incised. Abdominal hair fringe dense, griseous. Pronotum striolated. Apex of scutellum not beak-shaped. Length: i^mm. Hab. New Galloway {Cameron). Kleditoma melanopoda, sp, nov. Nigra, geniailis, tibiis tarsisque, piceis, alls IiyaliniSy. nervis testaceis ; antennis lo7igis,clava nulla. ?. Long. 27 mm.. Hab. London District. Black ; the knees, and fore tibiae, and tarsi, piceous ; wings clear hyaline, the nervures piceous. Antennae more than twice the length of the thorax ; the third joint nearly one half longer than the fourth ; the apical six joints longer and somewhat thicker than the preceding, but not forming a distinct club; the seventh joint shorter than the eighth. Occiput transversely striated; pronotum rather strongly longitudinally striated; sides of scutellum striolated; the cup lanceolate, the apical depression round and with two small foveae behind it; scutellar foveas large, deep, and longer than broad. Abdomen compressed, longer than the head and thorax united; the hair fringe long, griseous. Metanotum with an oblique slope, shining, impunctate, the centre hollowed, the sides keeled. Wings large. ? i68 Mr. Cameron on There is no described species with which E. vielanopoda can be compared ; nor can it be placed very well in any of Foerster's "Genera." The antennae come nearest to those of K.pygmaea; but the apical six joints form a well-marked club in it, and the form of the radial cellule is very different ; the radial cellule in K. iiielanopoda being formed as in K- brevicorniSy tetratoma, &c. EUCOILA GRACILICORNIS, Sp. nov. Nigra^ nitida, flagello antennariwiy ore^pedibusqiie, riifis ; alls flavo Jiyalinis ; antemiis corpore longioribiis ; clava hand discreta. Long. 4 mm. Hab. Banks of Clyde, near Cambuslang {Cavieroii). Black ; the flagellum and legs (except the basal three- fourths of the coxae) red ; the tegulae piceous ; wings yellowish-hyaline, the nervures testaceous. Antennae filiform> longer than the body, the sixth and following joints not thicker than the fifth, elongated, much longer than broad ; the third joint shorter than the fourth. Scutellum rugosely punctured ; the cup suborbicular, narrowed at the base ; the rim piceous ; the fovea at apex large, wider than long. Hair on sides of metanotum moderately long, griseous. Abdomen not much longer than the thorax ; its hair fringe, thick, griseous. Wings large ; first abscissa of radius about three- fourths of the length of second, and both are distinctly curved ; the third abscissa about the length of basal two united, slightly curved ; cubitus reaching to the apex of the wing ; apical fringe moderate. The male has the antenna:^ one and three-fourth times longer than the body ; the third joint is shorter than the fourth. Closely allied to E. similis, Cam., but that species has the antennae not much longer than the body, and with the apical eight joints thicker than the preceding, and scarcely twice longer than broad ; the wings are clear hyaline, the nervures paler, the cubitus does not reach to the apex of the wing, and the tcgul.x are entirely red. Hyinenoptera. 1 69 PROCTOTRUPID^. Epyris ORIENTALIS, Sp. nov. Niger ^ capite ptmctato ; nietanoto transvei'se striolato^ alls fusco-hyalinis. Long. 10 mm. Hab. Barrackpore, Bengal {G. A. J. Rothney). Antennae fuscous towards the apex; sparsely clothed with long white hairs; the third joint about one-fourth shorter than the fifth. Head shining, sparsely covered with long white hair; covered with large scattered punctures. Mandibles rufous towards the base and apex; sparsely covered with large irregular punctures and sparsely pilose. Pro- and mesothorax covered with longish fuscous hair; sparsely punctured ; parapsidal furrows complete. Meta- notum shining, transversely striolated, reticulated in the centre, and with two stout keels, which unite towards the apex of the metanotum; median segment transversely striolated. Abdomen at the apex covered with long hair. Legs thickly covered with white hair. Lower discoidal cellule complete; upper with the nervures obscure and faint. Epyris hispanicus, sp. nov. Niger, capite thoraceque riigoso punctatis, vietanoto y-carinato ; ore, inandibidis, pro-niesothorace, cum scutello, riifis,antennis testaceis, vel apice fuscis ; pedibiis nigris, t arsis testaceis, coxis, trochanferibus feniorihisque antccis, rufis ; alis fiiscis, basi fasciaque medio lacteis. Long. 4^ — 7 mm. Hab. Gibraltar r/./ IF^/^^r, R.NJ. Antenna stout, scarcel}- so long as the thorax ; the flagellum shortly and sparsely covered with a white pile, the third joint about one-fourth longer than the second ; the fourth is hardly so long as the second. Head sparsely covered with white hairs ; strongly rugosely punctured all over ; mandibles punctured at the base, the apex black. M 170 Mr. Cameron on Pronotum quadrate, almost transverse above in front ;• rugosely punctured and furrowed down the middle above,, the sides longitudinally rugosely punctured, almost striolated ; mesonotum punctured, but not very strongly, and rather irregularly; parapsidal furrows complete, diverging towards, the front ; scutellum punctured, if anything, more strongly than the mesonotum ; mesopleurse rugosely punctured ;, metanotum shining ; there is a stout central keel ; one on either side of it, which converge towards its apex, so as to almost touch ; at a greater distance outside this than is the second keel from the central, is another stout keel, which also converges towards the apex ; and outside this again, and quite close to the marginal keel, is another which runs almost parallel with the latter. The space between the keels is tranversely rugosely striolated, this being also the case with the median segment, but it is more regular and there is only a central keel. The sides of the metanotum project into stout teeth ; the apex is convex (forming almost the segment of a circle) ; metapleur^e irregularly reticulated- Abdomen shining, shorter than the thorax ; the apex and central segments somewhat thickly covered with longish white hairs. Legs thickly covered with a stiff white pile. Wings a little longer than the thorax ; the lower discoidal cellule is open at the apex. The above is described from a specimen 7 mm. in length,, and with the wings longer than the thorax ; but Mr. Walker sends specimens measuring from 4^ to ^^ mm. in length, which have the wings one-half or even one-fourth of the length of the thorax. In these the punctuation is less strongly developed, and the metanotal keels less distinct (especially those on either side of the central), but otherwise I cannot find any tangible differences. In the smaller specimens the punctuation varies in intensity ; the amount of red on the anterior legs varies considerably, and the antennae may be black, dull testaceous at the base. Hymeiioptera. 171 EpYRIS APTERUS, sp. 710V. Niger, nlatus; t ho race riifo, nigro inaculato ; basi flagello antennariiin, majidibulis, geniciilis tarsisque, rufo-tcstaceis, capite sparse punctato, nitido ; metaitoto tricarinato. Long, fere 5 mm. Hah. Gibraltar (/. / HW/'tv, R.N.). First joint of antennct curved, and thickened towards the apex; second a little longer than the third, which is somewhat longer than the fourth. Head shining, sparsely pilose; marked all over with shallow, distinctly separated punctures; eyes oblong, placed almost in the centre. Thorax shining, obsoletely punctured ; the prothorax quad- rate, the front rounded ; mesonotum and scutellum almost impunctate; parapsidal furrows distinct, but shallow and narrow; metanotum impunctate, the centre three-keeled, the central keel straight, the lateral converging towards the apex, which is almost transverse, but, if anything, retreating in the centre. Abdomen shining, the apex bearing stiff white hairs. The thorax is red, except the prosternum, an irregular splash in the centre above, the mesopleura^ in front, the metanotum, except the central keeled part and more or less of the metapleurae. The legs are covered with stiff white hairs. There are no wings. In general coloration this species agrees closely with E. Jiispanicus, but the second joint of the antennae being longer than the third, the head only slightly punctured^ the thorax scarcely punctured, the pronotum not furrowed in the centre, and the metanotum, only having three keels^ readily separate it. The complete absence of wings may make the generic position of E. apterus a little doubtful; but the fact that E. Jiispanicus shows a tendency to losing the wings, and the complete parapsidal furrows leaves no doubt in my mind that it is a true Epyris. 172 Mr. Cameron 07i Epyris tricolor, sp. nov. Coeruleus, flagdlo ajitejuiariun, coxis, tj^ochaiiteribiiSy fevioribus, abdominisque apice late, nigris; tibiis, tarsisqite anterioribiis testaceis ; tarsis posticis fiiscis ; abdoiiimis bast late riifo-testaceo ; metajioto tricariiiato ; alls fiiscis, nervis testaceis; stiginate radioqitc fuscis. $ . Long, fere 5 mm. Hab. New Forest (P. Cameron). Antennae stout, three-fourths of the length of the body ; the third joint fully twice the length of the second, which is a little shorter than the fourth. Head broader than long, retreating behind the eyes, which are large, reach in front beyond the base of the antennae and beyond the ocelli behind ; shining, punctured, the punctures moderately large, shallow, and distinctly separated ; a shallow furrow runs down from the front ocellus. Prothorax strongly punctured, longer than broad, narrowed and rounded towards the front ; the presternum bulging out. Mesothorax shining metallic ; marked with scattered shallow punctures ; parapsidal fur- rows complete, almost parallel ; scutellum very shining, obsoletely punctured. Metanotum between the keels trans- versely striolated ; the apex rounded, the bounding keel being continued on the inner side of the projecting sides, which are placed on a lower level than the keel ; the central keels narrow ; the central straight, the lateral slightly curved and converging towards the apex. Abdomen shorter than the thorax, shining, impunctate. Wings nearly as long as the thorax and abdomen united ; the two discoidal cellules completely closed ; the cubital ncrvurc is continued beyond the upper. Legs almost bare ; tips of the tarsi pale testaceous. Taken by myself in the New Forest early in June. Two British species of Epyris were described by Haliday in Ent. Mag. V., p. 519, namely: — E. niger. Metathorace truncato, dorso tricarinato et cancellato; abdomine convcxo; nervis costalibus conjunctis, and H) 'inerioptcra. 17^ E. siibcyaneus. Metathorace dorso reguloso, apice rotundato ; abdomine depresso ; nervis costalibusdisjunctis; areola prae brachiali a stigmatc rcmoto. The latter species was described by Walker in Ent. Mag. IV., p. 432., pi. xvi., f. 6, under the erroneous name of iW^^r West, and Westwood (Thesa. Ent. Oxon., p. 158) changes the name to Halidii, on the ground that the name Siibcyaneus is not characteristic. Westwood also describes in the above work two additional new species, namely, E. fraternus from Combe Wood, and E. sceva "ex Anglia." Thomson (Oef af K. Vet. Akad. i860, p. 453) describes a Swedish species E. bilineata, but from all these E. tricolor is readily known by the metallic blue head and thorax and testaceous abdomen. It may be as well to give the references to our British species. 1. E. tricolor^ Cam. supra. 2. E. niger, Westwood, Phil. Mag. 1832. i. p. 129; Haliday, Ent. Mag. V. p. 519. 3. E. stibcyaneiis, Haliday, Ent. Mag. V. 519, olim E. niger, I.e. IV. p. 432, pi. xvi. f 6. E. Halidii, West., Thesa. Ent. Oxon., p. 158, pi. xvi. fig. 6. 4. E. fratermis. West., I.e., p. 157, pi. xxx. fig. 2. 5. E. sceva, Westwood, I.e., p. 158, pi. xxxi. fig. 6. Note. — Dours (^Cat. Hymen, de France, p. 112) records "£". ruficollis, Gir."; but I cannot find any reference to such a species in Giraud's papers, of which, I believe, I have the whole; and, therefore, suspect it is a manuscript name. The practice of recording species under manuscript names is not only useless, but entails endless trouble in en- deavouring to find out if and where they have been described. Epyris rufipes, sp. nov. Niger, ftitidiis, sparse punctatiis ; breviter pilosus ; uietanoto aeieulato ; antennis, inandibiilis, tegulis, palpis, 1/4 Mr. Cameron on pedibiLsqiie, rnfis ; alls fere Jiyalinis ; stigniate fiisco ; nervis testaceis % Long. 5 mm. Hab. Mexico, Orizaba, December (//. H. Smith and F. D. Godnimt). Antennae as long as the thorax, stout, sparsely haired . the scape curved on lower side, dilated at the apex, as long as the following three joints united ; the second joint a little longer than the third, narrowed at the base. Head shining ; sparsely punctured, the punctures widely and irregularly separated ; thorax finely aciculated, irregularly punctured ; scutellum impunctate ; metathorax strongly aciculated ; a keel down the centre ; and on either side of this central keel are some irregularly waved keels, most of which do not reach the apex of the metanotum, on which there is a distinct keel ; median segment finely transversely striated, hollowed in the centre. Abdomen shining and impunctate ; the apical three segments covered with pale hairs. Lower discoidal cellule entirely obliterated. Legs stout, covered with whitish hair ; the fore coxa^ are for the greater part black. ErVRIS PUNCTATUS, sp. nov. Niger, crebre punctatiis, albo Jiirtus, vietanoto nitido, im- punctato, tricarinato; flagello antennaruni rufo-testaceis ; palpis, trochanteribiis, genicidis, tibiis tarsisqiie, testaceis; alis hyalinis; stigmato ftisco, nervis testaceis. $, . Long, fere 5 mm. Hab. Mexico, Orizaba, December (//. //. S/nit/i and F. D. Godnian). Antennae longer than the thorax, rather densely pilose; scape curved,as long as the second and third jointsunited ; the second one-third the length of the following, which is longer than the fourth. Head rugosely punctured; eyes projecting; front and oral region excavated deeply, the antennai originating from large tubercles, situated in the centre of the excavation ; mandibles large, punctured, three Hyincnoptcra. 175 toothed, reddish before the middle; the eyes are situated quite close to the base of the mandibles. Pro- and meso- thorax coarsely rugosely punctured, the pleurae more irregularly and less strongly; scutellum shining, bearing a few indistinct punctures. Prothorax considerably narrowed in front, the sides with a slight curve, the pronotum in front transverse, projecting above the elongated prosternum. Metathorax shining, impunctate, except in the centre of the metanotum, which is aciculated and bears three keels, the central reaching a little beyond the middle, the lateral not half its length, the central towards the apex having a few transverse stri^. The apex of the metanotum has not a distinct margin; the median segment impunctate, shining, semi-perpendicular. Abdomen shorter than the thorax, the apical half sparsely covered with white hair; the apex broadly testaceous. Legs moderately stout, pilose; the tibiae incline more or less to fuscous. Lower discoidal cellule completely traced. Proctotrupes MACULIPENNIS, sp. nov. Fulviis^ nitidiis.fulvo Jiirtus, mesopleuris sternoqiie, nigris; alls flavo hyalinis,fusco bifasciatis. Long. 9 mm. Hab. New Zealand, Grey mouth {Helms). Clypeus almost transverse, margined ; front carinate, the sides depressed. Propleura^ deeply excavated ; pronotum depressed in the middle, the sides broadly tuberculate ; scutellum raised ; a broad semi-circular furrow at its base ; post scutellum not raised ; a broad and wide depression on on either side of it ; a broad and wide furrow at the base of the metanotum, which on either side, in front of this furrow, projects into a large stout tubercle, and there is a sharper and somewhat smaller tubercle in the centre ; from the tubercles keels run down to the apex of the metanotum. Legs covered with a fulvous pubescence ; the base of the hind cox?e inclining to black. The fuscous cloud in the 1/6 Mr. Cameron 07i wings commences at the base of the stigma, and extends to the apex, but is interrupted above by a large yellow cloud, which extends to the costa, but not to the opposite side of the wing. The hind wings are yellowish, smoky at the apex. ICHNEUMONID^. PiMPLA Jason, sp. nov. Ferruginea ; nitida ; antennisy tibiisy tarsisqiie posticis^ nigris ; alis^ hyalinis, apice violaceis. ^ et S . Long. 15 mm. ; terebra 4 — 5 mm. Hab. Interior of Colombia ( Wheeler). Antennae as long as the body, stout, densely pilose. Clypeus rounded at apex, depressed slightly in front of it, and with a wide and deep furrow at the base ; face slightly projecting in the centre ; front depressed ; ocelli bordered laterally by a furrow, mesonotum bearing a sparse short pubescence ; scutellum with a deep, broad, wide depression at the base, this being keeled, the keel being continued down the sides of the scutellum to near its apex, where it becomes indistinct. Metanotum with two stout transverse keels near the apex. Petiole narrow, obscurely furrowed above at the base. The second segment bears a deep depression on either side at the base, and a longer and shallower one at the apex. Areolet oblique, elongated ; the curved recurrent nervure is received beyond the middle. BRACONDI^. BrACON DOLICIIOURA, Sp. 7Z0V. Niger; abdovmie pallide ochraceo ; facie longe pallide hirta ; alis fuliginosis. Long. 12; terebra 127 mm. Hab. Mountains S.W. of Bogota. Antennae densely pilose ; the scape with moderately long black hairs. Head shining, the vertex sparsely covered with long black hairs ; the face more thickly with pale fus- cous ; front moderately depressed ; the furrow narrow, but Hymenoptera. ijj deep and distinct. Thorax shining, impunctate ; the meso- notum sparsely, the metathorax more thickly and longly haired ; metanotum with a very gradual slope to the apex. Base of petiole very deeply excavated ; the inner furrow wide ; the outer narrow and placed almost beneath the edge. The oblique depression on the second segment is wide, moderately deep, shining and impunctate ; suturiform articulation shallow, curved, impunctate ; the apical branch almost obsolete ; the furrow on the next segment is shallow and not very distinct ; ventral apical segment ploughshare- shaped. Wings longer than the body ; cubital nervure curved upwards at the base. Legs stout, pilose. The ovipositor, long as it is, is hardly so long as in the Japanese Bracon penetrator Smith {Proc. Zool. Soc, 1877, p. 413, pi. xliv., fig, i). Smith, it may be added, figures and describes from Bogota an ichneumon, DolichoviiUis longicauda {I.e., p. 412, pi. xliv., fig. 2 and 2d), which has the body from 9 — 1 1 lines, and the ovipositor from 3^ — 6^ inches in length. EVAN 1 1 D^. GaSTERUPTION ORIENTALE, Sp. 710V. Nigrum, tJiorace, basique coxaruni posticariun, nifis; tJiorace rugoso ; capite laevo, albo-argeiiteo piloso ; alls hyalinis. Long. 15 mm. Hab. Barrackpore, Bengal {G. A. J. Rothney). Antennae not much longer than the thorax, stout; the third joint a little longer than the fourth, which is almost of the length of the fifth. Head smooth, impunctate; the face closely covered with a short silvery pile; behind the eyes bearing (but not above) a scattered pubesence, longer and more bristly than that on the face, hinder ocelli separated by about the length of the third antennal joint, and by a less distance from the eyes, which are distant from the base of the mandibles by about the length of the second 178 Mr. Cameron on antennal joint. Prosternum bearing long, dense, silvery hair; prothorax punctured in front. Meso- and metathorax rugosely punctured, running laterally into reticulations; sparsely covered with glistening white hair; median seg- ment transversely rugosely reticulated ; scutellum and meta- notum black; the latter densely covered with white hair. Abdomen covered (especially laterally) with a depressed white pile; the second and third segments dull red above. Hind coxae transversely striolated (but not strongly), punctured at the base. Hinder tibiae with a white spot on the inner side above the middle; metatarsus a little longer than the other joints united. Inner discoidal cellules separated. This is the first species of Gasteruption described from the oriental region. AmPULEX RUFICOLLIS, Sp. 710V. Niger ^ thorace ricfo, metanoti medio nigro; mandibulis rnjo-flavis; pedibtis aiiterioribus ex parte riifis ; alis hyalinisy ftisco fasciatis. Long. 7 mm. Hab. Gibraltar (/. / JF^/>^^r, R.N.). Head semi-opaque, closely punctured ; the carinate face transversely striated ; almost bare, except a fringe of white hair over the mouth, which is testaceous. Antennae bearing a sparse microscopic pile ; the scape and the middle joints beneath rufous ; the third joint twice the length of the fourth. Prothorax finely rugose ; mesonotum obscurely punctured ; parapsidal furrows distinct ; scutellum obso- letely punctured ; mesopleurae closely punctured, striolated in front ; the sternum covered with long white hair ; metanotum with a central and three lateral keels ; reticu- lated, the sides irregularly striolated ; median segment semi-perpendicular, transversely striated, thickly covered with white hair. Abdomen shining, impunctate, the apex thickly covered with silvery white pubescence. The anterior coxa^, Hynicnoptera. 1 79 trochanters, and the femora, tibiae and tarsi in front, the four posterior trochanters, and the middle femora in front are reddish ; the front femora are only black in the middle behind. The wings are very clear hyaline ; the cloud extends from the base of the stigma to the end of the third cubital cellule. The hind coxae are densely covered with silvery pubescence. The only genera in which this species can be placed are Auipiilex and DolicJmriis. Comparing it with the Indian species of Ampulex, the only tangible point in which it differs (that is of what might be regarded as of generic value) is that the petiole is thicker and curves more up- wards ; but as there is some variation in this in the known species oi ADipulex^ this can hardly be considered of much importance. There is also one cubital cellule less, the first transverse cubital nervure being obliterated. Also in this respect the oriental species are said to vary in this nervure being occasionally faint. In the form of the abdomen it probably more resembles Dolichurus ; but in that genus the first recurrent nervure is received in the second cubital cellule. As in Ampiilex, there is a tooth towards the middle of the claw. In the neuration of the wings I may add it agrees with the genus Rhinopsis, West, (an American genus). A careful comparison of it with a Central American species of Rhinopsis does not show any appreciable generic diffe- rence ; and if the neuration of A. riificollis be normal, i.e., if there are only two transverse cubital nervures, I do not see how it can be separated from Rhinopsis.^ and must, in fact, be regarded as pertaining to that genus, unless, indeed, the difference in the neuration between the latter and Ain- pulex be not regarded as of generic importance, in which case the two may be united. It is, however, worthy of note that this and the only described European species oi Ainp2ilex\\-d.\'^ only two trans- verse cubital nervures as in Rhinopsis, Further, they differ in i8o Mr. Cameron on being smaller, and in the bodies not being metallic green or blue as in the species which have usually been regarded as typical oi AmpiileXy e.g., A. compressa, and A. angtisticollis. They are, indeed, so unlike that it is probable that an examination of all the species of R/nnopsis might reveal some other generic distinction besides the difference in the neuration, in which case the name Ampitlex would be retained for the European species and for Rhmopsis (which must, in this case, be regarded as a synonym of Ampidex), while a new name would be required for the large metallic exotic species {covipressa^ &c.). The only known European species of Ampulex is A. fasciata, Jurine (Nouv. Meth. d. Class, d. Hym., pi. xiv., supp.) = ^?/r^/^^, Giraud (Verh. z.-b. Ges., Wien, 1858, p. 41 1 ). This is totally black and differs otherwise in many respects from A. ruficollis. GORYTES TRICHIOSOMA, Sp. 710V. Niger, dense longe Jiirtiis ; pnnctatiis, apice metanoti reti- culato; alls fusco-Jiyalinis. Long. 12 — 13 mm. Hab. New Zealand, Greymouth, (^Helms). The hair on the head and thorax is fuscous-black, long and rather dense ; on the base of the abdomen it is equally long, but sparser ; the hair on the rest of the abdomen is shorter and thicker. Head and thorax closely and distinctly punctured, shining ; the posterior part of the mesopleurae almost impunctate ; there is a large, somewhat triangular impunctate space at the base of the metanotum, the rest of the metanotum being irregularly rugose, running into reti- culations at the apex. Abdomen semi-sessile; shining; the petiole depressed in the centre at the base ; the basal three- fourths with an oblique slope, the apex on a level with the second segment. There is a shallow, but distinct, furrow at the base of the latter, this furrow being irregularly crenu- latcd. Apical segment acutely triangular, punctured like Hymenoptera. 1 8 1 the other segments and not differing from them. Antennae stout, as long as the abdomen ; the scape bearing mode- rately long, black hair ; the flagellum a microscopic down ; the third joint is a little shorter than the fourth. Wings hyaline at the base, the rest fuscous or fuscous-black, some- times with a violacious tinge ; the stigma and nervures deep black ; the first submedian nervure interstitial ; the first transverse cubital nervure received in the basal third of the cellule ; the part of the cubital nervure bounded by it and the first transverse cubital being curved ; the second recur- rent is received somewhat behind the basal fourth ; the portion of the cellule bounded by the recurrent nervures is about one-fourth longer than the top of the cellule. The third cubital cellule at the top is scarcely so long as the part bounded by the recurrent nervures ; the third trans- verse cubital nervure is more or less curved at the bottom. Submedian cellule in posterior wings appendiculated, i.e., not reaching to the end of the externo-median nervures, and before the origin of the cubital nervure = Gojytes sensii str. Tibiae and tarsi densely covered with a greyish pube- scence ; the femora sparsely with soft black hairs. Gorytes carbonariiis^ Smith (Cat. Hymen. Ins. IV. p. 366), also from New Zealand, can hardly be the species I have described, for the pubescence is said to be "thin," the meta- thorax "smooth," &c. Crabo CORA, sp. nov. Niger, apicefemofum anterionuii, tibiis tar sisqiie anterior i- biis, articulis 2 — ^ tarsorwn posticonim, tegulisqiie, fiavisy alts fere hyalinis. $. Long. 9 — 10 mm. Hab. Greymouth, New Zealand {^Helms'), Antennae black, the middle joints inclining to fulvous beneath; covered with a microscopic pile; joint two one- fourth longer than the third; curved, thickened, and pro- duced at the apex; the third with the apical half con- 1 82 Mr. Cameron on siderably thickened and produced, and a little shorter than' the fourth, which is thicker and still more produced at the apex; the fifth narrowed at the base and nearly as lon^^ as the fourth; the sixth narrowed at the basal fourth and obliquely thickened towards the apex, which is oblique and produced on the lower side; the other joints normal. Head wider than the thorax, semi-opaque, finely and closely punctured; a wide, shallow furrow runs down from the ocelli; the front laterally, and at the middle on the apex, and the clypeus, densely covered with silvery hair. Thorax semi-opaque, finely and closely punctured ; the sternum and pleura; and apex of metathorax sparsely covered with white hairs ; the metanotum almost impunctate ; the centre with a deep and wide channel, which becomes wider and deeper towards the apex. Petiole half the length of the abdomen ;. the apex clavate ; abdominal segments pale at their junction ; the apical segments densely covered with long white hairs, the apical segments impunctate, truncated at the apex. The apical joint of the two hinder tarsi is black ; the meta- tarsus is black, and the four anterior tibiae are more or less black behind ; the hind spurs are black. The tubercles and tegulse are yellow ; the scape may be more or less yellow beneath. Pronotum raised above the base of the meso- notum ; this raised part depressed in the middle in front and with a distinct margin on either side of this central depression. Tachytes Helmsi, sp. nov. Niger, opaais, breviter, argenteo pilosiis ; tegulis piceis ; alls fusco-violaceo-hyalinis. ?. Long. 9 mm. Hab. Grey mouth, New Zealand {Hchns.). Antenna; stout, as long as the thorax, densely micro- scopically pilose ; the third joint more than twice the length of the second and about one-fourth longer than the fourth. Head covered with dull greyish hair ; clypeus and sides of Hymenoptera. 183 the front with silvery pubescence ; eyes converging at the top and separated by more than twice the length of the third antennal joint ; a r»-shaped depression on the vertex, which has no dilatations, nor has the front ; clypeus broadly rounded, almost transverse at the apex. The silvery white hair on the thorax is moderately thick and long ; the median segment is depressed in the centre. Abdomen with the segments brownish-white at their junction and bearing a fringe of silvery hair, which is especially thick laterally ; pygidial area densely covered with bristly silvery hair ; the apex almost transverse, pro- jecting laterally into a pale tubercle. Legs densely covered with silvery hair ; the bristles pale ; the apex of fore tarsi dull rufous ; tibiae sparsely spinose. The second recurrent ncrvure is received a little beyond the middle ; and the two recurrent nervures are separated by a little shorter space than the length of the second cubital cellule at the top ; the second cubital cellule being there slightly shorter than the third. This species belongs to the genus TacJiysphex (Kohl). 1 84 Mr. Cosmo Melvill on the A survey of the genus Cypraea (Linn.), its Nomen- clature, Geographical Distribution, and Distinctive Affinities; with descriptions of two new species, and several varieties. By James Cosmo Melvill, M.A., F.L.S. (Received April lyt/i, 1888.) Cypr^A, or more classically Cypria, is derived from one of the many attributes of Aphrodite, owing, doubtless, to her worship not only having been inaugurated, but for long years principally centralized, in Cyprus, then a luxuriant and smiling island, teeming with industrial wealth.^ Horace addresses her as " Diva potens Cypri,"^ and Tibullus, when apostrophizing the goddess thus : " Et faveas concha, Cypria, vecta tua," '^ surely pictured her but lately risen from the foam, reposing in some glassy Nautilus shell, her most seemly fairy sea- chariot. Allowance must always be made for mythical as well as poetical license ; yet it is almost impossible to com- prehend how some old writers, as Rondelet, the famous chemist and natural historian of Montpelier, can have supposed the Cowry to have been the dreaded Echcneis^ or Remora, a sucking fish which, on the authority of Herodotus, so clogged the course of Periander's warships at the instance of Venus, as to stay the meditated execution of the youths of Corcyra, and hence, in gratitude to the engine that averted this wholesale massacre, the title of Cypria, or CoiicJia Venerea was bestowed. Certainly this is a primaeval instance of Beauty and the Beast, of earlier date probably than the well-known legend, but we argue that the Cowry ' .'l^^s Cyprium=:xu'7r^ov, copper. Plin. 34, §20. •^ Hor. Od. i. 3. I. • Tibullus iii. 3, 4. " Cf. Pliny N. H. 9, 25. Genus Cyprcea. 185 cannot have been the Beast, far more likely the gigantic Calamary, or Octopus, was intended, of which specimens of almost Titanic size abound in deep sea caverns in Sicily and the rocky Calabrian shore. Granted the name arose on account of the grace of form of these shells, it is a matter of some little difficulty to conjecture exactly the time ivhen it was bestowed upon the genus exclusively. Linnseus probably did not coin it himself ; he was fond of using ancient appellations, yet no mention can be found of it in Pliny or Aristotle ; indeed, as late as the time of Rumphius at the end of the seventeenth ■century, it was termed PORCELLANA, or Erythr^A;-'' it is probable, however, that about that date, or certainly not later than 1740, CypR/EA usurped these old titles, and it was, at all events, finally fixed, in strict accordance with the revised canons of priority by Linnaeus (xii. ed. "Systema Naturae") in the year 1767. Now, however, Cyprcea is, perhaps, the most conspicuous and generally known of all Mollusca. Although we have on^y one small representative of the family on our own coasts, the variable little Nun Cowry, {C. [Trirm] Eiiropcea, Mon- iagii), certain of the Tropical species are imported very plentifully. No sandal-wood box, forwarded from the East by native collectors, who abound at Singapore, Amboyna, and Ceylon, but is certain to contain at least twenty of the most ubiquitous and showy of the smaller kinds ; whilst of the larger, C. Ma7iriiiana, pa7tthcrina,, talpa, and tigris are well known as ornaments on many a cottage mantel-shelf. Owing to the protection the surface of the shell receives through its being more or less covered by the mantle of the • C. pantherina comes from the Red Sea, also some other beautiful species. *' K. rubro lucida concha mari," Tibullus ii. 4, 30, and cf. Prop. iii. 1 1, 16. The Meleagrina, or Pearl oyster, may however be more probably intended in these allusions — as fisheries for the purpose are known to have been carried on in the "Mare Erythrceum." N 1 86 Mr. Cosmo Melvill on the mollusc during life, a specimen in inferior condition is the exception, not the rule, and this fact adds to their abundance and, perhaps, popularity. (I.) Uses, coiiunercial or otherwise. — The Money Cowry {C. vioneta L.) is of commercial interest, from being used as a substitute for coin, especially in Africa and certain parts of India. This is a very abundantly distributed species, of less beauty either of form or colour than many of its kindred,, but of very marked individuality. It is collected plentifully throughout the Eastern Islands, especially in the lagoons, of the low-lying Laccadives and Maldives, in the Indian Ocean. About 3,200 Cowries equal a rupee in value. From a very remote period we read of these shells, or some allied species, being used for various purposes. The term Cowrie, or Gowrie, is derived from the Greek x"'^P"'-^i '^ little pig; and the xot,on'^, according to Liddell and Scott, was a 'small sea mussel, probably the porcelain shell,' which was used by the Athenian dicasts in voting : — so quoted by Aristophanes, ov xoLC)LvG)v ol^wi', aWa crTroi'cCJy.''^ and, again, i] ^fJTa X'lQov fie ttoii^gov t'0ov TCLQ yoipivaQ apidfiovfriyy Following the example of the Greeks, the Romans termed these little shells porei or porctili, whilst the French nowadays term them pou de mer ; and in the word porcelain we can also trace the same derivation. Some of the larger species, too, especially C. tigris and Arabica, are used for ornamental shell w^ork. The latter, when decorticated with acid, has a fine lilac surface ; the Lord's Prayer, and other inscriptions I have seen carved on these species ; also heads, as on the true Cameo shells, Strombus or Cassis, but the effect is usually inferior, the Cowry shells being hardly massive enough for this purpose. * Aristoph. Eq. 1332. •" Aristoph. Vespre. 333, 334. Genus Cyprc^a. 187 (II.) Fossil FovjHS. — The Cowries first appear in the Cre- taceous and Tertiary Periods : there are between ninety and a hundred fossil forms, mostly smaller than many of their recent congeners. Dr. F. Jousseaume published, some four years ago, a proposed subdivision of the genus, taking into consideration the extinct as well as the recent species ; — a very laudable attempt, but we can hardly agree with him in considering it necessary to propose no less than thirty- six genera, most of them new, for their reception ! His Zoila, for instance, formed for C. Scottii, Thersites, and Diarginata, his Mmixiena^ for C. Mauritia7ia, and Tronay for C. stercoraria and venusta, should surely be all included as very nearly allied, in one section of the genus ; and the same might be said for three more of his so-called genera LuriUy Zonaria, and Adusta, since spadicea, physis, and o?iyx, severally representatives of these three, are of extremely near affinity. And other instances might be adduced. I am very pleased, however, to find Dr. Jous- seaume and myself agreeing in several particulars, and, as I had not the opportunity of seeing his interesting article until I had drawn up the annexed list of the approximate relations of the species to each other, my conclusions have been in every way independent. He isolates C. 2tinbilicata^ C^ tessellata, and C. Childreni, allies C. stercoraria to C. vennsta, but includes C. lynx and mappa with the tigris section called by him Vtilgusella, which I am unable to do. C. miis and leucostoma, which would appear survivals of an other- wise extinct group, he places in the genus GisortiUy the type being the large fossil Ovida gisortiana (Val.). The puny little C. Adainsonii (Gray), again, is the only recent repre- sentative of some attractive fossil forms, of which C. elegant, and C. cancellata (Swainson) may be considered the types, peculiar from the surface being covered with raised reti- culated strict. 1 88 Mr. Cosmo Melvill 07t the (III.) Catalogues and monographs of the Genus. — Besides the monograph of Dr. Jousseaume just alluded to, and which was published in the Bulletin de la Soc. Zoologique de France^ 1884, the following catalogues, treatises, and monographs, which include descriptions of Cyprcea and Trivia^ exist : — Linne, C. Systema Naturae (Ed. xii.), 1767. Martini. Conchylien-Cabinet, Vol I., 1769. Perry, George. Conchology, 181 1. (Five plates of the 61 devoted to Cypra^a). Dillwyn. Descr. Catalogue of Recent Shells, 1817. Lamarck. Histoire naturelle d'Animaux sans Ver- tebres. Vol. VII., Ed. i., 1822, and Ed. ii., augm. parDeshayes et Milne Edwards, Vol. X., 1844. Gray, Dr. John Edward, F.R.S. Zoological Journal, 1 824. Wood, W. Index Testacealogicus, 1828. Sowerby, G. B. (the elder). Conchological Illustrations, 1837- Deshayes, G. R Encycl. Method., Vol. III. Jay, J. C. Catalogue of Shells in his Cabinet, 4 Editions. New York, 1835-52. Hanley, Sylvanus. Ipsa Linn^ei Conchylia, 1855. Kiener, L. C. Coquilles Vivantes, about 1840. Catlow and Reeve. The Conchologist's Nomenclator, 1845. Reeve, Lovell. Conchologia Iconica, Vol. Ill, 1845. Adams, H. & A. Genera of Recent Mollusca, 1858. Sowerby, G. B. Thesaurus Conchyliorum, 1870. (Vol. III. pars). Weinkauff, H. C, in Kiister's Conchylien-Cabinet, 1881. Roberts, S. Raymond. Monograph of the Family Cypraiidai, in Tryon, Man. Conch., Phila- delphia, 1885 ; also Catalogue of Porcellanid?e, 1869 ; Amer. Jour. Conch. V. Genus CyprcEa. 189 * Paetel, Fr. Conchylien-Sammlung, 1887, Berlin. Catalogue of all hitherto described recent Shells, 6 parts, all published. (IV.) Systematic position. — The Family CyprcEidce is placed amongst the Rostriferoiis Section of Gasteropoda Fro- sobranchiata, following the StronibidcE and TerebellincB, and immediately preceding the Ovulidce {A7nphiperasidce,Ad3.vs\s) and Pedicularidcc, this last curious little genus of somewhat distorted shells, living imbedded in corals. With Ovida (Brug.) there is, of course, the most near relationship of all other genera ; but no spire exists in the true Egg-shells at any period of growth, the colour is mostly pure white porcellanous, sometimes pink, yellow, or lilac, extremities more or less beaked, outer lip often toothed or plicate, imier lip always smooth. Head of the animal furnished with a contractile Snout. The Ovulce appear first in the Chalk, but are rare, and often confounded with Cpyrcea. About fifty-five recent species are known. The similitude of the family to certain forms of Cassis, e.g. C. rufa (L.) and C. testiculus (L.), in the toothed lip, is but superficial. Mr. Stutchbury separated these two species from the true Helmet shells, under the name Cyprceacassis, but they are now included in the subgenus Cassidea (Brug.). We are indebted for the accepted classification of the Mollusca, mainly to the researches of the late Dr. Gray, of the British Museum, Dr. P'orbes, Mr. S. P. Woodward, author of that admirable work, " Recent and Fossil Shells,'' and Messrs. Henry and Arthur Adams. This classification, founded as it is on the truest scientific basis, viz., the drawing of the characters not so much from the shell as its '■'Note.— Owing to the lamented death of Herr F. Paetel last October, at the age of 76, it is to be feared that this useful Catalogue may not be completed. Only six parts have been issued, down to the Ampullaridoi. We have also to regret the demise of Mr. G. W. Tryon, junr., of Philadelphia, author of the yet incomplete " Manual of Concholog}', " and other valuable w orks. 190 Mr. Cosmo Melvill cm the inhabitant, is full of inherent strength, and will probably hold its own, as regards its most salient features, against any proposed changes. (V.) A7iimal. — The Animal h?i?> been figured by Messrs. Adams, and by Chenu, "Manuel de Conchyliologie," Vol. I., f 7. In this latter a coloured representation of C. moneta is given, the te7ttacles are stout and gradually tapering, eyes W fi m^. Animal of Cypraea tigris (Linn.). situated on slight excrescences about one quarter the distance from the head, viajitle fastened into two folds, meeting over the back of the shell at the dorsal sinus, and likewise orna- mented with forked filaments, papillae, or verrucae, and sometimes they are smooth — the mantle is furnished also with a siphon, which is often fringed. T\i^foot is large, and simple, fastened at either end, frequently contracted in front. Head obtuse, furnished with a contractile snout, or rostrum. No opercuhim. Lingual Riband long, with seven series of teeth Lingual Dentition of C. tigris (L. ). Genus Cypnva. 191 (3, I, 3). According to Adams, each row is composed of " one broad, quadrate, uncinated axile tooth, flanked on each side by three hooked laterals ; outer lateral teeth conical, entire or toothed." The animals are often resplendent with gaudy coloration, and white, yellow, vermilion, and rose are mentioned as predominant. (VI.) Growth and recuperative power. — The Yonng Shell differs extremely from the mature, it is Bulla-shaped, thin, with a distinct spire often covered with a fine epidermis ; the pattern and markings, as a rule, blurred and hardly commenced. The whole of plate xxvii. of Reeve, Conch. Icon., is taken up with figures of Cowries in this state, and is worth consulting. During growth, another phase is entered upon, the shell somewhat solidifies, the lip and columella thicken and show more development, the dentition commences, and the pattern, usually in triangular or zigzag flames and waves, asserts itself. The third, or concluding period, is when the calcifying process of the dorsal lobes of the mantle applies its energies to the base, teeth, and sides, covering the whole shell with porcellanous enamel, and completing the now recognisable design. As regards the unique power attributed to this genus of shells, by one observer only, Lieut. J. B. Hankey, R.N. (whose correspondence with Mr. Lovell Reeve on the subject may be found in Conch. Icon. Cyp. pi. i. Letter- press), viz., that he had been " in more than one instance an eyewitness " of a Cowry dissolving and decomposing its own shell as a preliminary to enlarging its borders, with some solvent fluid secreted in its mantle ; far be it from me to cast a shadow of doubt on this officer's veracity or powers of discrimination, yet it does appear strange that no other observer has noticed this phenomenon, more especially as there are at this time five Naturalists at least 192 Mr. Cosmo Melvill on the in the Tropics to one in Lieut. Hankey's day, now nearly fifty years ago. This NaturaHst adds that when the Cowry had virtually become naked and defenceless, in a short time a thin layer, of the frail consistency of shell-lac, began to cover it, and it assumed the form of a Cymba, of the family Volutidse, but owing to the extreme delicacy of the organization, he could not preserve any specimens. (VII.) Generic and siibgeneric divisions, hitherto adopted. — Dr. Gray's subdivision of the genus, adopted with some modifications by Messrs. Adams, 1858, in their "Genus of Recent Mollusca," Vol I., p. 263, is as follows : — • CypR/EA (L.). Shell ovately cylindrical, polished ; spire obsolete, or concealed by enamel ; aperture narrow, linear, inner lip denticulated ; outer lip greatly inflected, denticulate or crenate. Type C. talpa (L.). 32 sp. Aricia (Gray). Shell ovate, dorsally gibbous, flattened at the base, the sides thickened and dilated, polished ; spire concealed ; aperture narrow, linear ; inner lip gently expanded and callous, dentato-lirate ; outer lip dilated, flattened and callous, dentato-lirate. Type A. annulus (L.). 21 sp. LUPONIA (Gray).-'^ Shell ovately pyriform, ventricose, smooth, polished ;, spire concealed, often depressed ; aperture narrow, linear, inner lip plicato-dentate, the plaits often obsolete pos- teriorly ; outer lip inflexed and crenate. Types L. tigris (L.), L. Algoensis (Gray). 59 sp. *Of L. Edentula (Sowb.) Mr. Roberts has made a genus Gaskoinia, the only characteristic of which is that the teeth are obsolete. As, however, .some specimens are slightly toothed, I see no necessity for maintaining this, name even as a subdivision. Giviiis Cyprcea. 195 Naria (Gray). Front of columella narrow, dilated into a sharp toothed ridge, shell smooth. Type N. irrorata (Soland.). i sp, CvPRi^OVULA (Gray). Shell oval, ventricose, surface covered with elevated striae^ aperture narrow, linear ; inner lip denticulated, outer lip inflected and transversely striated. Two species — C. capensis (Gray), C. Adamsonii (Gray). Trivia (Gray). Shell oval, rather depressed, surface covered with elevated, transverse ribs, or tubercles, spire concealed, aper- ture narrow, inner lip sulcated, outer lip transversly grooved. Type T. Europa^a (Mont.). 34 sp. Subgenus PUSTULARIA (Swainson). Back with elevated tubercles, extremities slightly pro- duced. Type P. pustulata (Lamk.). 4 sp. Subgenus Epona (H. & A. Adams). Shell globose, back smooth, or with elevated tubercles. Type E. cicercula (Gmel). 4 sp. These subdivisions are almost purely artificial, and do not ahvays hold good. C. carneola (L.), for instance, has two forms, one a typical Cyprmi, the other with flattened base, would have to be placed in Aricia. I am inclined to agree with Sowerby, Thes. Conch. III., in allowing merely a subgeneric rank to Trivia alone, and entirely ignoring all the others. In the early part of this year I received from Mr. G. B. Sowerby a shell which, while it possesses the facies, dentition, and raised striae on the lower surface, of Cyprceoviila Capensis^ has the form as well as markings of Liiponia Algoensis (these being Dr. Gray's types of his two genera), and a new and most important link in the 194 Mr. Cosmo Melvill on the chain of connection is thereby shown. I propose to call this C. amphithales^ and am convinced it is specifically distinct, having seen several specimens, all alike, though mostly a little worn on the dorsal surface, which is, however, always smooth^ specimens in fine condition having been lately sent home by Mr. Bairstow. As will be seen subsequently, I append to this paper a list of all the known kinds, with their synonyms and varieties, devised upon a circular system ; that is to say, although the species are necessarily arranged in what appears at first sight a tabular form — from Nos. i to 189 — I mean that No. 189 will bear the nearest link to 188 on one hand and to No. i on the other, and so on. The extremes that according to this circular catalogue are thus placed in juxtaposition, C. leucodon (Brod.) and C. Valentia (Perry), or princeps (Gray) are, to quote a very interesting writer,* " probably the tips of the branches of the Conchological staiiimbaimi or genealogical tree, which may have reached the limit of possible development in their own direction." Both of these will be discussed more fully in another paragraph, it will suffice to say at present that there would seem to be some divided marks of affinity to bind them to each other, isolated as they stand in the series. Again, the Trivice, hitherto usually considered a distinct genus, are intimately connected with the Cyprcea proper on the one hand through T. pustulata (Lamk.), the young of which Infringes closely upon Cyprceovida Adamsonii (Gray), and, on the other, through the numerous smooth varieties of Trivia stapJiylcca (L.), which trench upon C. Helvola (L.), var. Haivaiiensis, and the rest of the members of that section {Erosce) whose marginal pitting of the sides is also found in the varieties of siaphylcea just mentioned, e.g. polita (Roberts), limacina (Lamk.), etc. ' Notes by a Field Naturalist in the Western Tro])ics, by the Rev. H. H. Iliggins, M.A., 1877. Genus Cyprcea. 195 (VIII.) Geographical Distribution. — Mr. A. R.Wallace's'' six regions are, in the subjoined table, slightly modified, especially as regards (^), which here must be under- stood to comprise Europe alone, with the whole of the Mediterranean and the Azores and Madeira ; {e) Australia, New Zealand, Tasmania, and the Fiji Isles alone ; while (/) becomes much the largest and most important subdivision, embracing the Red Sea, Persian Gulf, India, the East Indies, and the whole of the rest of Polynesia. The extremely wide distribution of many of the commoner species of the genus causes the above alterations to be necessary, let alone the fact that Mr. Wallace's regions were proposed by him more with a view to the inhabitants of the land than of the sea. Of about ten or eleven species the locality is altogether doubtful. Region. No. of Species. Region. No. of Species. {a) Neai-ctic ; i.e.^ United 8 {d) Ethiopian ; including 32 States & Canadian Coasts, Madagascar and the Mas- Atlantic, and Pacific. carus Islands in the Pacific, C. de Verdes and Canaries {b) Neotropical; ?>., Mexico, and Central American Coasts, Gallapagos Isles, 28 in the N. Atlantic, also St. Helena and Ascension Isles in S. Atlantic. W. Indies and South (e) Atistraliaii- ; here sig- 48 America, Atlantic and nifying Australia, Tas- Pacific. mania, New Zealand, and the Fiji Isles. {c) Palcearctic ; here simply 8 (/) Oriental ; embracing 105 including European Seas Chinese Seas andjapanese, proper, with both shores E. Indies, Polynesia, Per- of the Mediterranean, the sian Gulf, and Red Sea, Madeiras, and Azores. also Indian Seas and Ceylon. ^"Geographical Distribution of Animals," by A. R. Wallace, F.R.S. &c. 2 vols., 1876. 196 Mr. Cosmo Melvill on the In Polynesia alone Mr. Andrew Garrett* found no less than 75 species himself, with many varieties. His valuable paper is to be found in the Journal of Conchology, Vol. II.,. 1879, pp. 165 sqq. And in Moreton Bay, Queensland, Mr. Brazier mentions Mr. Coxen and himself discovering 27 sp. — /. of Conch., 1879, p. 318. The same collector also enumerates {Proc. Zool. Soc. 1872, pp. 82-86) 39 species as occurring on the shores of New South Wales. The late Mr. G. F. Angas, who likewise collected largely in Australia,, published a list of Cypraea at various times in Proc. Zool. Soc. 1865-77, from that region, especially from the neigh- bourhood of Port Jackson, in which about the same number are reported. Again, in the list of Mollusca collected b\^ Dr. Anderson, F.R.S., Superintendent of the Indian Museum, Calcutta, in the islands of the Mergui Archipelago and coasts of Tennasserim, 16 Cypraea are mentioned by Prof Von Martens {Joiirn. Linn. Soc. Zool, Vol. XXL, p. 185 sqq.),, 1888. Of these, C. Saiilce {Gaskoin) from Elphinstone Island, is the only rarity. Several tropical species, e.g- lynx, Arabica, vitellus occur in the Bay of Yeddo, Japan (Lischke). Swinhoe detected eight common species only at Formosa, while Jickeli(/. B. Mai Ges. XI.) gives 30 species as occurring in the Red Sea. Mr. R. Rossiter, exploring in New Caledonia,^ mentions {Proc. Linn. Soc. N. S. IV. VI.,, pp. 817, 832) 60 species on those shores, whilst Mr. Philip P. Carpenter only noticed 7 sp.2itFaind.m^(Proc. Zool Soc, iS6^). The figures above quoted must be taken with all reserve, for there is every probability further researches in (d) and (e) will raise the figures nearer those attained by (/). * News has only lately been received of the death of this celebrated con- chologist after a lingering illness, aged 65 years, at his residence at Iluahine, Society Islands. Mr, Garrett contributed several very valuable papers to various learned Societies on the distribution of certain genera of Mollusca in the I'olynesian Islands, and had amassed a very large collection, one half of which (4,000 species) had been gathered by his own hands. '' Also cf. Crosse et Fischer, Les Mollusques de Nouvelle Caledonie. Genus CyprcEa. 197 One cannot help being struck, however, with the poverty of the new world compared with the old ; and I believe that in many other marine genera of shells, e.g., Conns and Mitra, the same proportionate inequality would occur, especially in the Neotropical South Atlantic Coasts. Conns cedo nnlli (L.), however, is a native of West Indies, and two of the recent species of Pleiirotomaria, which make up for many deficiencies of lesser note. When comparing the nearly allied genus Oviila^ the species of which are about fifty-five in number, the preponder- ance of those found in (/) is almost overwhelming. No. of Species. (a) Nearctic ... ... ... 3 (b) Neotropical (c) Palaearctic (d) Ethiopian (e) Australian (f) Oriental The localities in which the tropical 5 3 7 4 33 Cowries and OinilidcB are found are mainly amongst coral reefs, or in the sands near shelving rocks : w^hile certain of the Ovtilidce are attached to gorgonias, whose colours they often assimilate : they all move slowly, and are extremely susceptible of fear, feeding mainly upon coral zoophytes. But few inhabit the deep sea : only 13 species, mostly single individuals, are recorded as being found during the "Challenger Expedition," i^Ji-iZj^. Vol. XV., Zoology, p. 421, sqq.) {Rep. Expl Challeng., (IX.) Total Number of Species. — Paetel in his last cata- logue(i887) enumerates 223 of Cyprcea and Trivia combined, but various errata and duplications have to be expunged, reducing the total to 181. To this add eight, four being good species relegated by him to varietal rank, and four ' Ovula must be taken here in a collective sense, as embracing Volva and Cyphoma (both of Bolten), Simnia (Risso), and Calpurnus (Montfort). 198 Mr. Cosmo Melvill on the newly described C. Hungerfordii {Sowb.), C. RasJileigJiaiia {Melv), C. ampJiithales {Melv.), and C. caput draconis {Alelv.) which brings up the total to 189. In the collection now exhibited there are about 170 species, besides varieties, and several of these are type shells, notably some of those formerly in the collection of Mr. J. S. Gaskoin, who for years made a special study of the Cowries, and whose whole series was acquired by Mr. T. Lombe Taylor, of Starston Hall, Norfolk, the dispersion of whose vast stores in 1879 made an unusual stir in the conchological world. (X.) Prominence and isolation of some Species. — In na other genus of shells do certain members of it take sa distinctive a place ; there are, for instance, six kinds which add the charms of being almost or quite unique to their beauty and unusual forms. Amongst these first to be noted is : Cyprcea Icucodon (Broderip), described in 1828, Reeve C. I. f 23, and cf. Sowb. Thes. Conch., pi. iv., f 19, 20, a large handsome species between three and four inches in length, tawny with a few large round white spots, base tawny,, teeth very strong, deeply sulcated, white. No locality known. This has been unique in the National Collection for sixty years, and was considered by Mr. Lovell Reeve to be, with C. princeps, the most valuable of all yet discovered shells. A slight affinity in shape with this latter, and in the arrangement of the teeth with C. sidcidentata (Gray)"" may be traced, but it does not very nearly approach any known species — recent or fossil, nor could it be an undue development of any other kind. C. princeps (Gray). — This, originally described by Mr. Perry^ as C. Valentia, which name has priorit);, from the ' C. sulcidentata (Gray) is connected with C. arenosa (L.) and ventriculus (L.), but differs from all except leucodon (Brod.), in its deeply channelled tooth- grooves. It is a shell of some rarity. ^ Mr. George Perry in 1811 published a large folio volume, in which many Gcjius Cyprcea. 199- first known specimen having been sold by Mr. Humphrey to Lord Valentia,a patron of science in the last century, is even more extraordinary a shell than the last. Figured by Perry^ Conch., pi. xxiii., f. 2 ; by Sowerby, Thes. Conch., pi. i., f. 1,2; and by Reeve, Conch. Icon. pi. vi., f. 20. Its length is very nearly four inches. It is yellowish, tinged with purplish rose, painted over the dorsal surface with yellowish brown mark- ings, clouded on each side with a large darker blotch, at each extremity there are three rows of brown lines, sides with blue and brown spots. Base white, teeth also shining white. Recent discoveries have resulted in five specimens, all exactly similar, in addition to the original shell in the National Collection. These six are disposed as follows : — 2 in the National Collection, South Kensington. I in Coll. Zool. Soc, Amsterdam. I in Coll. Miss Saul, Bow Lodge, London, N. I in Coll. Dr. Cox, Sydney, N. S.W. Dredged off New Guinea Coast. I in Coll. — uncertain. The original specimen was called the " Brindled Cowry of the Persian Gulf," in old Humphrey's handwriting, but no other specimens have been known to come from that region, I believe. Mr. Perry mentions Amboyna, but that place must always be taken with some reserve, being a trading centre where such things are imported from a distance. C. guttata (Gray). — This shell evidently belongs to the Lamarkii and erosa section of Cypraea, and yet there are shells were delineated and described for the first time. Unfortunately he does not appear to have taken the trouble to consult previous authors, hence his writings abound with duplicate names, glaring errors, description of young shells as separate species, and the like. He has fallen under the lash of subse- quent writers, especially Messrs. Sowerby and Reeve, who ignore all his descrip- tions, but in justice to him and to the law of priority, where his species can be deciphered, many of the paintings being very fanciful, it is only right to attach his names — C. primeps (Gray.), nebidosa (Kien.), titrdus (Lamk.), and melanostoma (Leathes), thus become Vaiejiiia, Siirinai/iensis, ovata, and came/o- pardalis (all of Perry). 200 Mr. Cosmo Melvill on the no closely connecting links. I am inclined to think C. fiiscodentata and capensis may not be so far removed from it after all ; and in C. bicallosa (Gray) with its large varieties, ingloria and Aubiryaua, a slight resemblance may be traced. The length is about 2}^ inches. Shell yellow-fawn, of light texture, sprinkled with several large and small round white spots over the dorsal surface ; on the base and over the sides the teeth extend, which are bright orange, and ridged. The localities given are China, N. S. Wales, Red Sea, and New Britain, but I doubt these being substantiated, except, perhaps, the first and last, this being recorded by Mr. Hobson (1879). It is probable, from its thinness, that it is a deep water species. The specimens known arc seven, or, at most, eight in number, disposed as follow : — 1 in National Collection (not very good), cf. Reeve, Conch. Icon., pi. viii., f 30. 2 in Miss Saul's Collection. I formerly in Dr. Prevost's Collection, Alengon (sub- sequently in M. Grasset's, of Algiers, and now in the museum, Dijon, France). I in the Leyden Museum. I in Mr. J.C. Melvill's Collection, Prestwich (Fig. 7). This specimen is one of the finest known, and was formerly in the collection of Mr. Hugh Owen, from whom it was procured through the agency of Mr. R. Damon, of Weymouth. It is the type figured by Sowerby. {TJies. ConcJiyl.y pi. xvii., f 104, 105). I in Mus. Acad. Scient, Philadelphia, presented by Dr. T. B. Wilson, a fine specimen. I believe Herr Paetel, of Berlin, also possesses one. N.B. — This species has been long known. Martini (1769) figured it in his " Conchylien-Cabinet," Vol. I. Genus Cyprcea. 201 Some authors imagine C. Jenniiigsia (Perry) to be a synonym, but neither the figure (ph xix., f. 4) nor the description bear out this theory. I will refer to this again under the head of " doubtful species." C. Bardayi (Reeve). — A small, deep water form. Length a little over i inch. It is white, sprinkled over with tawny yellow, the extremities and unusually developed teeth, quite unlike any other species, bright yellow-orange, the labial teeth overlapping the base. Sir David Barclay, Bart., a most experienced Concholo- gist, and resident for many years at the Mauritius, dredged this off I. Diego Garcia. He allowed it to pass from his hands, thinking that more would reward his research, but, to his disappointment, another specimen has not turned up. The original and unique shell adorns the collection of Miss Saul. The other two extremely scarce species are C. Broderipii (Gray) and C. vemtsta (Sowb.). Reference will shortly be made in another place to the former of these, and the latter, whilst differing in colour (being of a pale creamy fawn,) and in some other particulars from C. stercoraria (L.), can hardly claim an isolated position in the genus. Miss Saul and Dr. Cox, of Sydney, possess the only specimens yet known to exist. C. mtrantmm (Martyn). — The far-famed Orange Cowry, termed by Chemnitz the " Aurora Solandri," was for many years considered the most esteemed of the genus, as it is still by far the most conspicuous. The length of the full grown mollusc is nearly 4 inches, — shining, globose, orange, within darker, teeth bright orange, base bright white. The Fiji, Loyalty and Friendly Islands, produce this shell. It is considered the badge of Royalty amongst some of the savage tribes, hence specimens coming to this country are occasionally found to have been perforated with holes, so that they might be strung together as a necklace. The natives of these Islands now know, or more than know^, O 202 Mr. Cosmo AIelvill on the their value, and two might be obtained at the marts in London for the price at which one inferior specimen could be obtained in Fiji at the present time. Mr. Marrat considers this species is very near, if not identical with, C. inappa. I can hardly agree with him. The yellow teeth seem to me the only link of affinity, and I am strongly of opinion that it has no congeners in the genus. C. testudmaria (L.) is a very isolated shell. In length about 5J^ inches, oblong, narrow, whitish brown, back marked with burnt sienna — brown and black, like tortoise- shell, besprinkled, in the adult, with indented white punctures, teeth smallish, white. A common species from the East Indies, but one of the handsomest of all. No other species, excepting C. Bregeriana, has the peculiarity of the small white specks, but some affinity in the cylindrical shape with G. argus (L.) may be traced. C. zcvtbilicata (Sowerby). — The resemblance to C. pan- tJierina^ of which it was thought once to be a monstrosity, is entirely superficial. It is depressed in front, with produced extremities, the spire deeply umbilicated, teeth brownish, markings pale fawn-coloured brown. Length, nearly four inches. A species, formerly very rare, dredged abundantly and without any variation, except an occasional white variety, in Australia, (var. alba of Cox). C. lynx (L.). — It may surprise some conchologists to find this spoken of as an .isolated species, but in attempting an arrangement of exact affinities I have had much difficulty. The nearest relation it possesses is undoubtedly C. IValkeri, with which it agrees in form, and coloration of the teeth interstices. It is variable, but always known by its oblong shape, clouded bluish and brown markings, with occasionally a dash of red, base and teeth white, base often with peculiar longitudinal sharply cut angled depression, which is very characteristic, interstices between the teeth invariably Genus Cyprcea. 203 bright orange red. Length normal, i to i^ inch. Air. J. M. Williams, of Liverpool, has a magnificent specimen, 3 J^: long., ij.4:iat. Native of all Eastern Seas. Abundant. {a) Williamsi {var. nov.). — Base suffused with orange red, pattern on dorsal surface much blurred with fawn colour. Length 2 in., lat. i]^. In JMr. Williams' coll. A striking colour variety. {b) Caledotiica (Crosse). — Distorted var., with extremities elongated, and unequally produced. Rare. New Cale- donia, cf. Tryon, Man. Conch, pi. xiv. f 98. C. tessellata (Swb.). — Dorsal surface tawny, with three broad bands ; sides squarely marked with black-brown blotches bordered with white, and two chesnut-brown spots ; base pale tawny and white, banded transversely ; teeth orange ; mouth straight, narrow. Length i ^ inch. Rare. Eastern Archipelago. New Zealand has been recorded, but I doubt its occurrence there. Only very few specimens are known otherwise than in a decorticated state. Those belone:- ing to Miss Saul and the late J\Irs. De Burgh surpass all others. C. Childreiii (Gray). — Transversely ribbed throughout, pale coloured, extremities angularly expanded below. This last development does not occur in any other species. Native of Polynesia. G. Adainso7iii (Gray). — To the unique peculiarities of this species, as recent, I have already referred. As Mr. Sowerby aptly observes, young specimens of Cyprcea piistidata (L.) are allied to this. It is a native of the Philippines and Mascarene Islands. C. irrorata (Solander). The prominence of the anterior columellar teeth dis- tinguishes this species from any other, hence Dr. Gray created a new genus for it, Naria (Descr. Cat, Cyp., p. 12, 1832). Native of the Low Archipelago, Paumotus, etc. I think there are several points of connection between this somewhat isolated species and fimbriata, inicrodon, etc. 204 Mr. Cosmo Melvill on the (XI.) Groups of tzuo or three in close affinity with each- other, otherzvise soniezvhat isolated. C. talpa (L.). C. exits ta (Sowb.). Both these must surely have descended from a common ancestor, but the distinction is never failing, and known at once. The latter differs from the commoner and more widely distributed talpa in being more pyriform in shape, teeth more numerous, smaller, and somewhat immersed,.- aperture narrower. While G. talpa is found commonly in the Eastern tropics, C. exusta is confined to the Red Sea,, but it is a great deal more than a local variety. C. inns (L.) C. leucostonia (Gaskoin). The latter, which is rarer, has often been confounded with C. niiis^ indeed, it was not till 1843 that Mr. Gaskoin differentiated the two. The complete absence of teeth in the latter, the white base, and the heavier and white appearance of the shell, with one or two other distinctions of minor importance, amply distinguish them : but they are not nearly allied to any other of the genus, though a fossil form or two is rightly connected with them by M. F. Jousseaume, Natives, C. mus of the Mediterranean, and W. African shores., C. leucostonia, Arabian coasts. C. lurida (L.). C. pidchra (L). C. controversa (Gray). Isabella (L.) var. On the upper side these three are very similar, all being bluish-cinereous with two brown spots at either extremity. Below, however, the common lurida is wide-mouthed, with coarse dentition, C. pulchra and controversa have a narrower aperture, but the latter is pure white both as to the base and teeth, with the extremities yellow spotted as in its type C. Isabella, the former being olivaceous, with small, fine, some- what obsolete teeth, of a reddish tint. Germs Cyprcea. 205 C. birida is common in the Mediterranean and part of the Atlantic Ocean, ptilchra only found in the Red Sea, and controversa from the East Indies and Mauritius. Mr. R. C. E. Stearns {Proc. Ac. Phil., 1878, p. 399) thinks this variety ■distinct, and signalises it as having been found in California. Has this been confirmed ? C. Broderipii (Gray). C. 7iivosa (Broderip). C. vitelliis (L.) C. camelopardalis (Perry), C. melanostovia (Leathes). The reason I call attention to this quaternion is that» while they are all very nearly allied to each other, two of them are only distinguished by characters not seen at a glance, but when seen, proving how extremes meet, while C. Broderipii is one of the rarest and most beautiful of known shells. It is the largest of the four, measuring over 3 inches in length, and is globose, the dorsal surface tinted rose-colour, with brown network pattern overspread. Be- neath, the teeth are long and well developed. Base pinkish. Native of Madagascar. Six specimens are known ; of which — I in National Collection, S. Kensington. 1 formerly in Mr. Hugh Owens' Collection. 2 in Miss Saul's Collection. 2 — rdispositions uncertain. C. vitelliis (L.) and C. nivosa (Brod.). — Both with near affinities to the preceding, are yet at first sight so close to each other as to appear hardly even varieties. And yet few species are so distinct. In the common vitelliis a widely distributed East Indian species, the pattern of pure white spots is first deposited by the mantle of the animal, and then the grey-brown colour is enamelled over, but thinly, so as not to conceal the now slightly blurred and somewhat indistinct spots. In nivosa^ on the other hand, the grey- l)rown colour is first deposited, and then the next, clear cut 2o6 Mr. Cosmo Melvill on the eye-like holes are cut out, as it were, by some secreting juices ; leaving them clearly defined, and there is no sign of the blurred lateral striae, so conspicuous in vitellus. C. dania (Ferry), Conch, xxiii., 3, has been supposed to be nk'osa, and thus to claim precedence of title. But I am convinced, on examining Mr. Perry's figure, that vitellus was intended^ for the ' hair-like marks at the sides ' are not only mentioned in this description, but also delineated. Broderip's name will therefore stand. This species is very rare ; found at the Mauritius. My specimen came from Mr. Lombe Taylor's collection. The dentition of both these is identical. C. vitellus (L.) (ci) sarcodes (var. nov.). — A colour variety, of pale uniform flesh colour, otherwise as in the t}'pe. Figured. Sowb. Thes. Conch., pi. vi., £31. G. cainelopardalis (Perry) was for many years confounded with vitellus, but the absence of lateral striation, the clear- ness of marking, and the smoky black interstices between the columellar teeth distinguish it. Common in the Red Sea. Better known by the later name of ^nelmiostoma (Leathes). C. pulcJiella (Swn.). C. pyriforviis (Gray). Two beautiful and rare shells, allied to each other, and with a connection, too, with G. Walkcri, but otherwise isolated. This latter, however, has a characteristic violet tinge, never found in the two under observation, and through this shell there may be a connection with G. lynx (L.). C. pulchella (Swn.) is truly pyriform, whitish, dorsal sur- face pale brown spotted, with or without a central deep brown blotch, sides spotted, base white, shining, teeth extending over the centre of the base, and labial teeth well developed, red. Length i % inch. Chinese Seas. C. pyriformis (Gray) and its small variety G. Sniithi (Sowerby). On dorsal surface pale cinereous, mottled with darker. Truly pyriform in shape, teeth on the outer lip Gemis Cyp7'CEa. 207 white, on columella red, but not extending far over the base. Eastern Seas. Length i^^ inch. G. moneta (L.). C Annulus (L.). 0. obvallata (Lamk.). Although kept distinct here for the sake of convenience, I think these three are really forms of one species. Typi- cally they are all distinct, and easily discernible, but the varieties are many, especially of moneta, of which the best known is icterina (Lamk.) a smooth variety. Barthelemeyi (Born) is a distorted produced variety from New Caledonia. M. A. T. Rochebrune has added ten so-called species to this section from moneta and annulus. He gives the distribution as extending from Japan to Corsica {G. Merca- tonun {Rochbr.), and from the Sandwich Isles to Zanzibar. It may probably have been accidentally introduced in the Mediterranean Sea. Most of these new forms are figured in Tryon. Man. of Conch., Cyp., pi. x., xi., and xxiii. C. No2L7nee7isis (Marie) is a curious form of anmihis with double orange lines on the back of the shell. C. obvallata (Lamk.). {a) calcarata (var. nov.). Shell dull, chalky white, uncoloured, otherwise as in the type. Two live shells in good state of preservation exactly similar in Mr. Williams' collection. The geographical distri- bution of this is not so extended as are the former and better known species. It is recorded, however, from Cook, Society, and Paumotus Isles (A. Garrett), Australia, and New Caledonia. The depressed centre of the dorsal surface is very characteristic. (XII.) Upon Variation. — Far be it from me toaugment the mass of literature that of recent years has flooded the world on the most important and, as yet, only partially solved question of variation and limitation of species. The doctrine 2o8 Mr. Cosmo Melvill on the of specific immutability, is, in these enlightened days, vigorously assailed, but, as just pointed out, there are certain forms of this genus apparently unapproached and with no close relationships i7iter se. The case is widely different with others ; and the question arises, 'Is a general trinomial system of nomenclature to be preferred for these, the specific, or binomial term being rigorously restricted to those promi- nent types that are the highest result of evolution in their own particular sphere?' Such a proposal has many advocates ; and I am prepared to go thus far with them, in signalizing certain leading colour varieties and other aberrations from the types, either in form or some other peculiarity, of which, in the course of long investigation, I have seen the frequent recurrence. I agree entirely with the late Dr. Gwyn Jeffreys' remarks (/. of Conch. III., p. 234): " Until an International Court has been established to decide the long-mooted question of not only what is a species, but also what are the limits of so-called species, it is useless to do more than argue it. Every naturalist has a perfect right to his own opinion, and time will be the only test of such opinions being correct or erroneous." But if excessive latitude were given to such a trinomial system, there would be great fear of a too minute critical differentiation, especially in genera that ' sport ' more than do the Cowries. Any conchologist, for instance, who has perused Mr. Marrat's researches on the genus Nassa,* in which are enumerated no less than 1,321 links by which the whole is bound together, would shrink from the task at being called upon to bestow appellations upon such a vast concourse (there having been hitherto only 250 recognised commonly), and thus the literature of the subject would become wofully embarrassed, and clogged with such a plethora of dog-Latin, as almost to deter the student of the future from voluntarily entering upon so formidable a study. *On the Varieties of Shells belonging to the genus * Nassa,' by F. P. Marrat, Liverpool, 1 880. Genus Cypr(Ba. 209 Briefly, then, it is evident that as a plant, insect, or shell may be considered a perfect representative of its species only so long as all the distinguishing traits and combinations of character exemplified in the original type are present, so it becomes a variety^ when, owing to some local or other cause, one or more of these typical characteristics disappear, and change it to that extent. In the genus under discussion, too much reliance must not be placed on either forvi^ colour^ texture^ sice, pattern, nor (always) dentition ; but three or four of these points will be found present in every variety, while, crowning all, there is nearly always an indefinable and intuitive per- ception that will enable a specialist to recognise and relegate to its proper position with confidence, any individual he may be asked to decide upon. {a) Form. — The chief variations are either undue pro- longation, as in some specimens from New Caledonia, a more effuse growth than is ordinary, or a contracted and stunted form, generally thickened laterally. Monstrosities occur in many of the species. iU) Colotir. — Colour varieties affect some species far more than others ; they run into each other very closely, e.g., C. tigris vars. : but certain stand out, constantly recur, and are always recognisable. The Sandwich Isles and the Island of JMatiritins each possess races of Cowries, of various species, in which the whole shell has become semi- pellucid, and of a golden yellow or straw coloured hue, almost free from markings. These probably come from deep water, and, in a few species, unicolorous green varieties also occur. ■ • {c) Texture. — Varieties from deep water are sometimes thinner than usual, and in certain forms, e.g., G. carneola, the lateral thickening spoken of under {a) gives a greater ponderosity to the shell. id') Size. — Certain species, as C. lynx, carneola, etc., often attain unusual size, three or more inches in length, when 2IO Mr. Cosmo Melvill 07i the normally only a third or quarter of that extent. Again^ 0. caiirica has a very small variety, not much more than ^ inch, and many other kinds vary in a similar manner. {e) Pattern. — This has already been spoken of. The design of the adult Cowry is, as a rule, wonderfully uniform. Occasionally as in C. tigris, var. iontJiodes and a form of G. /j'/Lv,\a.rgQ triangular blotches cover the dorsal surface, and, as in stolida var., gelashna certain spots, present in the type, disappear. Again, the pattern is often blurred over by the last deposit of colouring matter,as in C.Arabica var. niger, the black variety of mappa, C. Jielvola var. Mascarena, and others. (/) Dentition is the least variable point, and the greatest holdfast in detecting a species, in nine cases out of ten. But in C. stolida, G. staphylcBa, etc., much inconstancy is shown, so even this cannot always be relied upon. No hybrids appear to have been ever detected, unless, indeed, some of the nearly akin forms we are noticing in this paper prove such ; but these are questions for the future scientist to decide. It is to be hoped now, with the establishment of Marine Biological Laboratories, we shall be able in the course of a few years to learn something more definite of the life-history of these creatures, whose external skeletons are but an insufficient sign-post for guidance, and, till this achievement, we must be content with only very imperfect knowledge of the affinities and relationships of so interesting a group as Cypraea. (XIII.) Notes on certain species and proposed varieties. Cypraea inappa (L.), (Type, cf. Reeve, Conch. Icon., pi. vi., f i8 ; Perry, Conch, pi. xxiii., f. i, as alga). Three well known varieties of this well known Eastern shell occur. {a) panerythraiyds. nov.) ; cf. Sowb., Thes. Conch., pi. v., f. 28. Shell uniformly suffused with pale red or deep rose, which is generally deepest at the base. Teeth plain, or only slightly tinged with yellow. N. Caledonia, etc. Genus Cyprcea. 2 1 1 {b) siibsignaia (van nov.) ; cf. Sowb., ut stiprd, f. 24, 25,. 27. Base spotted with bright Hlac, and conspicuously blotched with darker purple towards the centre ; teeth con- spicuously orange. S. Brandon Shoals, Indian Ocean, etc. {c) nigricans (Mont.) ; suffused with black, extremities rostrate. Var. vionstr. N. Caledonia. C. pantJieriiia (Sol). (Type, Reeve, Conch. Icon., pi. iii., f. 7 ; Sowb. T. C, pi. xi., f. 69, 70). Five colour varieties. ia) badionitens (var. nov.). Shell smaller than the type, somewhat transparent, dorsal surface partly suffused with light golden brown, spots well nigh obsolete. A rare and striking variety. {b) theriaca (var. nov.). Shell entirely, with the excep- tion of the extremities and base, suffused with rich golden red-brown, not disposed in blotches as (ci). Figured in Sowerby, Thes. Conch., pi. xi., f. 71. Common. Some speci- mens are almost, if not quite, blacky and a monstrous form also occurs pretty frequentl}' with warty extraneous growth,, principally at one or other extremity {theriaca distorta). {c) albonitens (var. nov.). Spots smaller, and more dis- tant, giving therefore greater prominence to white body colour of the shell. [d) juvenca (var. nov.). Very pale fawn colour, spots almost obsolete, owing to the enamel being laid on more thickly than is ordinary. This variety, which usually has some tendency to distortion, often resembles C. nnibilicata (Sowb.), the base, however,will at once show its specific affinity. ie) syrijiga (var. nov.). Shell with pale lilac tinge. Spots dark purple. Uncommon. Note. — Weinkauff, in Kiister's •' Conchylien-Cabinet,'* has figured this and many of the above colour varieties. C. tigris (L.). (Type, Reeve, C. I., pi. iv., f. 12, a and b ; Sowb., T. C, pi. xxi., f. 172 — 3 — 4). The painting of this well known species is most variable ; the principal colour Y-arieties that stand out are as follows: — 212 Mr. Cosmo Melvill on the {a) flavonitensiy^x. nov.). (Sowb.,Thes.C., pl.xxi., f. 175.) Suffused with rich yellow or orange. Spots often more sparsely distributed. A very beautiful and well known form from Mauritius chiefly, also from the Fiji Islands. Vj ib) hinnulea (van nov.). Pale grey brown coloured, spots almost obsolete. Of very infrequent occurrence, compared with the last variety, corresponding to C. pantherina\^x.jitvenca. (), amahilis (Jousseaume), is said by the author to differ in the more produced extremities, which are a little re- curved, narrow bands dorsally, and only the inner lip purple tinted. I have never seen this. It is figured in Try on. Man. Conch. Cyprcea, pi. xiv, f. i, 2. '' The Rev. R. B. Watson (Rep. on Gast. Challenger Expedition, Vol. X\'., p. 424) considers this a good species, so do Messrs. Roberts, Reeve, and Sowerby. Genus Cypnp.a. 217 These species are usually considered forms of one, but I fancy there is more difference between them than is usually given credit for. C.fabula is ovate, stunted, not spotted at the extremi- ties, dorsal surface suffused with brown, laterally thickened, base white, mouth narrow, teeth coarser than in the next. C.felina and its variety iirsellus (Gmel.) (the latter charac- terised by white base as opposed to yellow in the typical form) are cylindrical, not thickened laterally, spotted very clearly, with large blotches at the sides, dorsal surface cinereous, brown extremities spotted, mouth wide, teeth about fourteen in either lip. C. caiirica (L). The type of this abundant mollusc is well given by Sowerby, Thes. Conch., pi. xxiii., f 188, 189, and Reeve, Conch. Icon., pi. xi., f 46. Reeve says truh-, " This specimen varies from long and rounded forms with thin sides, to short and depressed with thickened sides." Long. max. i^s inch. A small full grown form from my collection may be seen in the plate appended (fig. 9), only ^ inch in length. East Indies, general. {a) oblongata (van nov,), (fig. 8). Shell oblong, thinner than the type, and often of much greater length, say 2]/^ inches, somewhat effuse, back pale green, densely clouded over with brown confused markings. Sides rounded, thin, scarcely spotted, in one of my specimens dark banded, teeth about eighteen, not so prominently developed as in the type, base usually yellowish white, the base of typical caurica being usually flesh colour, and mouth wider. Same localities as above. There is every gradation between this and the typical form. This may be C. dongata (Perry), cf. Conch., pi. xxii., f. 5, but the delineation is, as usual, fantastic in the extreme. {b) concava (Owen). An almost distorted state from R. Gambia ; cf. Sow., Thes. Conch., pi. xxix., f 318, 319. [c] obsciira (Rossiter). A black banded var from New Caledonia, p 21 8 Mr. Cosmo Melvill on the C. cruenta (Gmel.) is very nearly allied to the preceding, and the variety coloba (fig. 7), so called from the stunted appearance, is also figured in Sowb. Thes., f. 190, as caurica var. ; it would appear nearer this species : the base is always brighter coloured, and teeth interstices bright red. I possess stunted caurica, with which this var. cannot be mistaken. There are two species, C. tabescens (Sol.) and C teres (Gmel.), allied to C. catirica (L.). The former of these is at a glance known by its teeth, small and numerous, and white base ; but on the dorsal surface it is often impossible to recognise it as distinct from caurica. And I have another variety which is tending to the form of teres. The two are always, however, distinguish- able, and I do not doubt the genuineness of the specific rank they hold, C. teres itself being a narrow, cylindrical, delicately marked shell, with fine, almost obsolete teeth. It ranks among the more prized of the smaller kinds. Cf. Sowb., pi. xxvii., f 259, 260. C. tabescens (Solander). Type, cf. Sowb., T. C, pi. xxvii., f 261, 265. {a) latior (var. nov.). Cf. Reeve, Conch. Icon., pi. xiv., f 66a. A pyriform shell, broader and more stunted than the type, with brighter coloration, and very distinct dorso- lateral spots. A handsome and rare form, almost sub-specific. {b) pellucens (var. nov.). Transparent form, from the Sandwich Isles, dorsal markings indistinct, pale brown. Some specimens large and effuse, others pyriform and broader as var. {a), {c) alveolus (Tapparone Canefri). I do not know this form. It is reported from Mauritius, from whence also I have seen unicolorous, thickened, dark green enamelled specimens, shape as in the type, which may be signalized as id) elaiodes. C. Rashleighana (Melvill). /. of Conch., V., p. 288, 1887, pi. ii., f. 26 ; also fig. 3 in photographic plate appended. GeuHs Cyprcxa. 219 As it is only four months since this was described, it may not be amiss to transcribe the particulars. "C. testa ovata, antice subprolongata, dorso convexiusculo, lilacino, tribus brunneis fasciis decorato, fascia centrali distinctiore et latiore, lateribus albis parcipunctatis, extremitalibus imma- culatis, dentibus parvulis, albis, basi alba nitente. Long. 18 mm., lat. 1 1 mm. Habitat ? " "A very pretty addition to the known species of cowry, albeit of small size, the disposition of the brown bands on the lilac ground is a little like the arrangement in C. san- giiinolenta (Gmelin), the shape and upper surface slightly recall C. macula (Adams), though the underside has a per- fectly different disposition of teeth, C, macula being allied more to th^fimbriata section of the genus. Nothing at all nearly resembling this cowry is to be found in the National Collection, or in the latest monograph (that of Mr. Raymond Roberts). With this shell I have associated the name of my late friend Mr. Jonathan Rashleigh, Junr., of Menabilly, Corn- wall, who died December, 1872, aged only 27. His collec- tion of Cyprsea was extremely large and perfect, and had he lived he would have made great mark in a science to which he was profoundly attached. Of this unique shell I am glad to be able to give a photographic representation (fig. 3). I consider it now nearer to C. tabescens than inacnla^ or any of \he Jimbriata section, but differing as much from the stunted form of tabescens on the one hand, as C. teres does from the smaller, more elongate variety. C. stolida (L.). Type, Reeve, Conch. Icon., pi. xiv., f. 6y^, 67^. Sowb., T. C, pi. XXX., f. 327, 329. {a) moniontha (var. nov.), (fig. 4). Dorsal surface rounded, not humped, with one rounded blotch only, and occasionally this is absent, sides streaked and speckled, teeth not so prolonged, white. Length in largest specimen i^ inch. This is intermediate between the type and C. brevidentata (Sowb.). A common form, almost a sub-species. 220 Mr. Cosmo Melvill on the (b) diauges (van nov.), (fig. 5). Yellow, shining, semi- pellucid, shape as in type. One pale central dorsal blotch, otherwise unspotted and uniform pale yellow, including the extremities and teeth. Bears the same relation to the type that C. Helvola^ pale van, bears to that shell. Mauritius. {c) gelasinia (van nov.). Shape as in type, with flattened dorsal surface, pale olive green, very delicately pale brown spotted, and with no dorsal blotch, extremities pale fawn. Teeth as in {b). Mauritius. A beautiful variety in the National Collection. id) Crosseii^2s\€). Alarge,attenuated, almost monstrous, form, from New Caledonia. N.B. — G. brevide?ztata {Sowh.) diXid 0. erytJirceensis (Gray) both seem extreme forms of this species. I would refer to Reeve, Conch. Icon., pi. xiv., f. 63, for a differentiation of the latter. The characters are clear enough when com- pared with the type, and not with intermediates. It is,. however, always of uniformly smaller size. Found at the Red Sea, as far S. as Zanziban My largest specimen only measures ^ inch in length. C. brevidentata (Sowb.) is well figured in Thes. Conch., pi. xxx., f 325, 326. A very rare form, from Borneo, of which but few examples are known in European or American Cabinets. C. clandestina (L.). The type of this common species is pale whitish, oblong, ornamented with very fine zigzag brownish yellow lines, sides and base white : teeth very well marked. It varies extremely in size, the largest specimens I have seen are in the collection of Mn J. M. Williams, of Liverpool, nearly i inch in length. id) Candida (Pease). A pure white unmarked variety. {b) A rttiffel/i Qoussesiume). Is this the same as C. asellus van figured in Sowerby, Thes. Conch., pi. xxx., f 327*? It compares well with the plate in Tryon. Man. Conch., pi. xvi., f. 61. I recollect this specimen in the collection of my late friend Mn Rashleigh, but have had no opportunity of com- G 671213 Cypnca. 221 paring it, as since his death in 1872, his collections have been left packed in the Bedford Pantechnicon, London, and are not in a condition, therefore, to be consulted. {c) Mr. Williams also possesses a very ovate form of this species, marked dorsally with leaden blue. Should subse- quent investigations cause this to be entered as a good variety, I would suggest the name van C. passerina {cf. Sowb., Thes. Conch., f 534). id) abcrra7ts (Ancey). I do not know this form. C. capensis (Gray); cf. Reeve. Conch. Icon., pi. xvii., f %6. Sowb.jT.C, pi. xxix., f 306, 307, 308 ^ This shell, with C. Adamsonii (Gray), were originally made sole types of the genus CyprcBoinila, the surface being ribbed transversely. Liipoiiia (Gray) was characterised by the pyriform shape, smooth, polished, spire concealed and depressed, inner lip plaited-toothed, outer inflexed and crenate. Type, L. Algo- ensis (Gray); cf. Sowb., Thes., pi. xxix., f 311, 312. As announced previously in this paper, I recently obtained a specimen of a very extraordinary shell from Port Elizabeth, S. Africa, which appears to unite these two forms, types of two different genera of Gray, in its own person. The following is the description : — C. amphithales (sp. nov.), (fig. 19).^^ C. testa rotundato- pyriformi, subumbilicata, stramineo-alba, lateribus brunneis maculis conspersis, latere dextro extremitatibusque ambabus anguste marginatis, apertura angustiore quam in C. algoensi latiore quam in C. Capensi, dorso omnino laevi, brunnea centrali macula decorato, basi transversim liristriata, labio •dentibus octodecim, quasi liri-duplicatis, columellaribus ut in C. capensi. Long, i in. Hab., Port Elizabeth. " The annexed plate (fig. 20) shows perhaps the finest specimen known of C. capensis (Gray), which is in my collection. The dorsal blotch is of a fine rich brown, and the transverse lirse unusually clear and sharply cut. ^ The specific name, aupi^aX-m, blooviins;^ out on both sides, was suggested by the ramifications presented on the one hand towards Cypr3eovula, and on the other towards Luponia. 222 Mr. Cosmo Melvill on the The upper shoulder of this new form resembles C. algo- ensis (fig. 2i), with which it is of uniform size. In shape it assimilates either shell ; it is not, however, deeply umbilicated, as is G. capeusis, the base is white, with numerous striae, the converging lins developing into fine labial teeth, two lircC meeting at the tooth projection, eighteen in number, while I have counted as many as twenty-five on well developed C. capeusis. The columellar teeth, as in that species, are represented by the fine projecting lira^ alone, thus differing from all the Lnponice^ which have developed teeth on both sides, with the exception of L. edentula. But the smooth dorsal surface, size of the aperture, and the spotted lateral margins, are as in Luponia. G. gangrenosa (Sol.). Reeve, Conch. Icon., pi. xviii.,. f gGa. In the typical form, the tips, fuscous above, orange beneath, are characteristic. {a)Boivijni{K.\QnQY),^g.g6b. Rientzii (Dunk.). This is a large shell, dorsal surface grey, the sinus usually marked by brown streak. Extremities uncolourcd. Very close to erosa (L.), van a. cf. Sowb., Thes. Conch., f 232. From Zanzibar. {b) vielanosema (var. nov.). Smaller, the extremities of dorsal surface with very wide, black, suffused extension of marking, sides white enamelled as far as dorsal sinus. I have seen fine specimens of this in the National Collection, and in that of Mr. Williams. From Mauritius. This may be what Dunker intends by his var. Rientzii, but authors seem much mixed in their opinions, and the name and description arc hopelessly confused with Boivinii. C. erosa (L.). Type Reeve, Conch. Icon., pi. xi., f 43. Sowerby, Thes. Conch., pi. xviii., f in — 112. There arc several constant varieties of this common and well-known species, the type of which may be described as follows : — Shell ovate, oblong, somewhat flattened, but few specimens exceeding long. r6o, lat. vi2 mm. The back buff- Genus Cyprc^a. 223 coloured, with many small round white dots, more copiously besprinkled over some parts than others, the sides in the type callous, somewhat extended, pitted, and crenated, teeth (in largest specimen) about nineteen, very strong and well developed, underside white, but rarely spotted, livid- blotched at the sides, this being almost central, and broadly square. Habitat, India, Ceylon, coast of the Pacific Islands, including Mauritius, coasts of tropical Australia, in fact universally distributed over the East. {a) pJiagedaina (van nov.), (fig. 1 1). Sowb.,T. C, pi. xviii., f 113. Without the livid lateral blotches ; unspotted shining white underneath, teeth about eighteen, not so prominently developed as in the type, and much resembling van Boivinii of G. gangrenosa. Back pale, light greenish brown, spots often very confused and indistinct. (J)) chlorizans{y2.x.x\ov?),{^g.\2). Dwarf 'So long., '60 lat. Form as in type. Lateral blotches conspicuous both on upper and lower sides. Back very dark olive green, spots clear, numerous and distinct. {c) strajninea (van nov.), (fig. 10). Shell semi-pellucid, back delicate transparent pale ochreous yellow, spots barel}- visible, livid lateral blotches present, teeth about sixteen, very well developed, underside pure white, shining. Hab., Mauritius, deep waten Size as in type. {d) 7iebrites (van nov.), (fig. 13). Sowb., Thes. Conch., pi. xviii., f 114, 115 ; Tryon. Cyp. f 90. General shape slightly more compact and stunted than in the type, varying (in my seven specimens) from I to v^o inch in length, colour warm flesh, back yellow-brown, the lateral blotches, which are most conspicuous, black-brown, and extending towards the centre, not visible below. Extremities markedly lineated with red lines. Teeth well developed, uncoloured, but not to such an extent as in the type. Base pale red-brown with linear brown lines and dots, almost exactly similar to C. ocellata^ with which species and typical ei'osa is here pre- 224 Mr. Cosmo Melvill on the sented a link ; indeed in the largest of my specimens of this variety some of the dorsal spots are distinctly ocel- lated. I have never, however, seen in C. ocellata, or any of the " spiirca " group, the slightest symptom of the square lateral blotches, so characteristic of erosa, though absent in one of its varieties. Locality, Borneo. C. ocellata (L.) differs mainly from all these varieties by its greater distinctness of ocellation and marking. It is a neater and more compact shell in every way. {a) palatha (van nov.), (fig. 14). Ocellations less pro- minently coloured, with a tendency to become obsolete, otherwise as in the type. This variety connects ocellata with erosa still more closely, the two distinctions which still remain being absence of blotches on the sides, more distinct lateral clouding, and the conspicuous orange-brown tinting of the teeth and extremities on the underside. The speci- men in the plate is in Coll. Mus., Owens College, Manchester, formerly in that of Mr. Reginald Cholmondeley, of Condover Hall, near Shrewsbury. 0. spicrca (Linn.). Cf. Sowb., T. C, f 118 — 122. This common Mediterranean and Atlantic Island species is not so variable as C. erosa ; some of its forms are more pyriform, and the marking is more distinct, often with slight ocellation on the dorsal surface; I hold that C. flaveola (L.) is of true specific rank, although I am not quite so sure that C. ceiniica (Sowb.) from Mauritius is not a more beautiful and tropical form of spiirca, var. {a\ and as such I have placed it in the subjoined table. I certainly have intermediates. Sowcrby (Thes. Conch., pi. xxvi., f 238 — 240) remarks upon the dorsal white spots being round and clear. I have a specimen with distinct trace of ocelli, as in spiirca. C. flaveola seems to be constant in small size, oblong form, and clear dorsal mark- ing. It connects the erosa-spitrca section with the cribrarice. C. spurca (L.). {b) Verdensiiun (var. nov.). Smaller than type, compact, sides slightly thickened, dorsal surface spotted Germs Cyprcsa. 225 in a rather confused manner, brown, extremities lineated, teeth finer than in spurca^ base white, somewhat spotted. Habitat, St. Vincent, Cape de Verde Islands. It much resembles a small form of C. turdus (Lam.), ovata (Perry). Allied to C. Thoinasi (Crosse), Jotir. de Conch., 1865, pi. vi., f 3, of which I have only seen description and figure, the habitat being unknown. I hesitate before pronouncing them identical ; the columellar teeth are described as being semi-obliterated, size 7 inch. If it were not for the constancy of the lilac base in C. Listeri (Gray) and the chestnut-brown hue of C. Helvola, how like they are to some forms of species we have just been commenting upon ! But Listeri is not a variable shell, and the peculiarity just mentioned always seems to distinguish it. Through it we come to C. albitginosa (IMawe) and poraria (L.), also with annulated ocelli on the back, and purplish base. C. Helvola (L.) is one of the most easily distinguishable, and yet most variable of the genus. The only species with which- it could possibly be confounded Is C. citrina (Gray), which has more teeth, and yet not so prominently developed, dorsal surface olive brown, with rounded spots of paler colour, a rare form, found In Ceylon, Mauritius, and off X.W. coast of Australia (^fide J. F. Bailey sec. Roberts). Sowb., Thes. Conch., pi. xxv., f 218, 219. The type o{ Hel- vola is figured in Reeve, pi. xv., f 72 ; Sowerby, pi. xxv., f 214 — 216. A most abundant Eastern species. Found in every group of Polynesian islands worked by Mr. A. Garrett ; also in India, Ceylon, Mauritius, &c. {a) Mascare?ia (var. nov.). Smaller, and of richer uniform burnt sienna brown colour, almost or entirely obliterating the white, grey, and brown spotted dorsal ornamentation. Native of the Mauritius. This is a colour variety, and I have traced every gradation to the type. C. chalcedouia (Perry), pi. xix., f 6, is apparently intermediate between this and the type. 226 Mr. Cosmo Melvill oji the {b) argella (van nov.). Shell usually oblong-ovate, sides not thickened, colour orange-brown, entirely enveloping the surface, the star like white dots appearing clearly defined over the back, the effect being exactly antagonistic to the normal condition, where brown specks appear on the dorsal surface on a greenish or bluish-white ground. I have four specimens of this variety, and have seen many others. Habitat, with the typical form. if) Hazuaiiensis (van nov.), (fig. i8). Pellucid, shining,, straw-coloured on both sides. There are two forms of this well-known variety, one incrassated laterally, bearing a strong superficial resemblance to C. cernica (Sowb.), the other with straight sides. Often the extremities, of so con- spicuous a lilac in this type, present a pale reflection of that colour ; otherwise they are uniformly straw-coloured. From the Sandwich Islands. Also cf. Sowb., T. C, pi. xxv., f 217. C. poraria (L.). Type Sowb., Thes. Conchyl., pi. xxvi., . f 236 — 237. An abundant Eastern shell. The lilac-backed unspotted young shells are very bright and beautiful. A curious monstrosity is mentioned by Brazier {Proc. Linn. Soc. NS. IF., VI., p. 202), destitute of white dots, and with the aperture shaped liked the figure 8. (a) Kanaiensis (van nov.). Pellucid. Pale yellow with purple tinge. From Kauai I., Sandwich Isles. Another of the characteristic Sandwich Island varieties. C. Laniarckii (Grdiy). Reeve., C. Icon., pi. x., f "^y., Sowb., Thes. Conch., pi. xvii., f 106, 107. Shell ovate, somewhat ventricose, slightly prolongated at either extremity, pitted at the sides, teeth about sixteen on either side, back ochreous,, profusely dotted with large and small round white spots, some of them ocellated, but occasionally with no signs of ocellation, extremities lineated as in C. turdus and C. erosa. Sides scarcely thickened, brown-spotted. Length i^ in., lat. ]/Q inch. Locality, Mozambique, &c. {a) redUnita (van nov.), (fig. 16). Shell somewhat stout, Genus Cyprcea. 227 slightly flattened at the base, extremities less produced than in the type, but more so than in C. tiirdiis, aperture fairl}- wide, two last anterior labial teeth distinct and projecting, as in Lantarckii and iniliaris. Dorsal surface pale-ochreous, indistinctly marked with obscure whitish spots, laterally thickened with white callosity on each side, and a double row of brown spots (almost becoming blotches in one specimen), which impart a special character at first sight. Size about the same as the type. I take this shell to be very well developed and full grown Lamarckii. I had at one time, some eighteen years ago, when I gave the MSS. name of redimita to the speci- mens then acquired at a dealer's in Liverpool, imagined the species was a new one. I have found an example among the Cholmondeley shells now at Owens College, rather larger than my own, but not so well marked as that now photographed. The underside is the same as C. turdus, and were it not for the projecting ridges of the two last labial teeth, which are never found in that shell, I should have been inclined to connect the two species more closely. C. iniliaris (Gmel.); {a) magistra (var. nov.), (fig. 6). \ very large variety, lately acquired through Mr.G.B.Sowerby, from Japan. Character the same as in the type, but teeth very well developed and size, long. 2^, lat. i^ inch. I have seen five or six other specimens in no other way differing. It is a handsome shell, and in fine condition ; it slightly resembles C. guttata on dorsal surface only. I consider C. ebnrnea (Barnes), often reckoned a mere albino form of this, a sufficiently good species. C. iniliaris (Gmel), C. Lamarckii (Gray), and C. Listeri (Gray) are commented upon by the Rev. R. Boog Watson, B.A., F.L.S., in his " Report on the Gasteropoda, Voyage of H.M.S. Challenger," Vol. XV., pp. 424, 425. To quote his remarks : 'Tn classing the Challenger specimen (of C. iniliaris, 228 Mr. Cosmo AIelvill on the collected in eight fathoms, off Wednesday Island, Cape York) as Ginelin's species, I mean simply that it agrees with shells bearing Gmelin's name in the British Museum. My own opinion is, that these are the same as others marked C. Laniai'ckii (Gray), and that both are distinct from C. erosa (L.), of which Dillwyn (Vol. I., p. 461, No. 50) regards Gmelin's species as the young, while Deshayes simply unites them, followed herein by Gray {Zool. Jour. Vol. I., p. 504), who, however, at the same time resuscitates the Cyprcea niiliaris (Gm.) in the form of two new species, C. Laniarckii and C. Listeri, of his own making, but one of which at least, if they be good species, ought to have borne Gmelin's name." He then quotes Kiener, Reeve, Sowerby, and Wcinkauff as further complicating the question. I think the following distinctions amply serve to diffe- rentiate successfully any examples of the species that puzzled Mr. Watson : — C. niiliaris (Gmel.). A^^z^^r possesses lateral spots ; dorsal surface covered with small white round spots, which are never eyed, or, at all events, extremely rarely. C. Lamarckii (Gray) always has lateral spots, dorsal surface with spots larger, round, and often ocellated. C. Hnngerfordii (Sowb.), 1888. This very handsome addition to the genus, procured by Dr. Hungerford at Hong Kong, is conspicuous for its pyriform shape and coronal of spots wreathing the dorsal surface. Sides white enamelled, thickened. Teeth fine, about twenty-four labial. Base as in C. ca r7zico lor {D\xc\os). Long. ly. inch ; lat. Js inch. I think should be placed between onyx, spadicea, and p/iysis ; to var. achatidea of this latter it approaches, but not very nearly. C. subviridis (Reeve). Conch. Icon., pi. xii., f 48 ; Sowb., Thes. Conch., pi. xxii., 176 — 178. Differentiated successfully by Mr. Reeve in 1835, having till then been confounded with ei^rones. A local species ; the dorsal Gemis Cypnca. 229 blotch is occasionally absent. A large variety occurs in New Caledonia {cf. Sowb., f. 176), and a beautifully coloured form (^id., f 358), is figured as being in the Lombe Taylor Collection. C. errones. (L.). Sowb., Thes. Conch., pi. xx.. 156, 157, 158. This species mainly varies as to the presence or absence of the brown dorsal blotch, and the plain or saffron colour of the teeth ; the specimens vary much, also in size, the smaller being the most brightly coloured. {a) cJirysopJi(za (var. nov.). Surface entirely coloured golden brown, enamel of base and sides shining, pale yellow, teeth and form as in type. A most beautiful colour variety in my collection from Port Blair. Andaman Islands. {U) C. Coxi (Brazier) and {c) C. SopJiicE (Brazier) are varieties ; the latter only differs in more lateral development of white enamel, and yellow teeth, and of this I possess a fine example ; the former a pale brown uniform variety, from N. W. Australia ; dentition and base as in the type. In the Cholmondeley Collection, Owens College, Manchester. C. cribraria (L.). Cf. Reeve, C. I., pi. xvi., f 81. Sowb., Thes. Conch., pi. xx., f 161 — 164. {a) translucida (var. nov.). Of this well-known and handsome species I have pellucid varieties from the Sand- wich Islands, which have been named Peasci, but this is a misnomer. It will be better to rechristen them translnciday as Peasei (Sowb.)^ is preoccupied by a different species. Form and dentition as in type. {U) Exnioiithensis (var. nov.). Another fine form I noticed recently in the Natural History Museum, S. Kensington. In this the dorsal markings are very rich blackish brown, the white spots more sparse ; long, in size about i inch. Habitat., Exmouth Gulf, W. Australia, collected by T. H. * C. Peasei (Sowb.) figured in Thes. Conch. XX., 166, 167; and a curious monstrous var. of the same, from Mauritius, is figured Proc. Zool. Soc. XLVL, f. 13, 14, 1878. 230 Mr. Cosmo Melvill on the Haynes. Mr. J. Michael Williams has another specimen approaching this. The dorsal covering matter seems to have been twice deposited, causing a very rich effect, with partial eclipse of the round white spots. This possibly may be C. coimna (Perry, Conch., pi. xxi., f. 5), but the plate and description are both bad, and identification difficult in con- sequence. Connected with C. cribrarici'^ are an assemblage of seven or eight species, all bearing considerable resemblance to it in the disposition of marking. Of these, C. esontropia (Duclos), a broader, more pyriform shell, is connected with the type by C. Peasei (Sowb.), which is a translucent Sand- wich Island variety, appertaining to both esontropia and Gaskoinii. C. cribellimt (Gaskoin) is a dwarfed form, with similar dorsal ornamentation. C. fallax (E. A. Smith) is perhaps only a fine large, more pyriform variety of cribraria, with smaller white spots and paler dorsal surface. C. Gaskoinii (Reeve), of which I possess the type specimen formerly in Mr. Gaskoin's collection, is a beautiful shell, straw-coloured marking, with clear cut ocelli, but I have very great doubt whether it be not an extreme form of esontropia. C. Cnniingii (Gray)^ is more distinct, a very graceful attenuated pyriform shape, resembling G. Macandrei (Sowb.), and C. Beckii (Gaskoin), in a greater degree than the other species. This last was included in the Trivia by Messrs. H. & A. Adams, owing to some strange oversight. The cribraricB more nearly run into each other than do most of the sections of this genus, and though cribraria, :i C. Coxeni (Brazier). {Proc. Zool. Soc, 1873, pi. xlviii., f. 10). I have seen the type in the National Collection, but would hesitate before relegating it to the cribrarice, as Mr. Brazier proposes, the dentition being altogether different. ^ C. couipta (Pease) is but a variety of Cicmingii from the Kingsmill grou[) (A. Garrett) and Phoenix Island (Harper Pease), a single example in each case. The dorsal sinus is branched, hinting at some malformation in the mantle, the result, however, being a beautiful little shell, now in the National Collection. Cf. Sowb., T. C, pi. xxxi., f. 351. Genus Cyprcea. 231 ■esontropia, cribellum^ Gaskoiiiii are typically distinct, I should never be surprised at all being eventually united. C. carneola (L.). Reeve, Conch. Icon., pi. ii., f. 19 ; Sowb., Thes. Conch., pi. iii., f. 11 — 13. Type. — Reddish flesh colour, with four or five bands of a darker hue of the same tint, extremely variable in shape. ]\Iy largest specimen 3^/^ in. long, the smallest full grown I inch. The sides have more or less callous deposits. Every gradation exists between the large elongate shell, the sides not thickened, and the smaller with flattened sides, resembling an Aricia. Teeth purple-violet. Very abund- antly distributed throughout the East. {a) Loebbeckeana (y^ Qink^ufT). Sowb.,Thes., pl.321, f 322. No bands of colour on dorsal surface, teeth uncoloured. Mauritius. 'My specimen of what I think is this, is of the usual translucent deep water character of so many Mauritian shells. {b) Jiahnaja (var. nov.). Dorsal surface covered with 'greenish callous deposit of enamel. Teeth purple, base greenish. Mauritius. From coll. Gloyne, collected by M, Robillard. I have seen a larger specimen of the same variety in the Lincolne Collection of Shells, Peel Park, Salford. An almost exact resemblance to a pickled olive may be traced, suggesting the varietal name. {c) propinqiia (Garrett). I think this is only the smaller solid form. Mr. Garrett says the number of teeth is but 25 to 30, form of arenosa. Paumotus and Society Isles. Cf. J. of Conch., 1879, p. 117. C. Isabella (L.). This common species mainly varies in {a) controversa (Gray). An only apparently sinistral shell, back with no black dashes, base broader than the type, teeth not quite so fine. ifi) limpida (var. nov.). Uncoloured, transparent. Sand- wich Isles. I have likewise seen deep olive green trans- 232 Mr. Cosmo Melvill on tJic lucent varieties, with base \'ellowish white, and the orani^c painting of the extremities almost or quite disappearing. C. stapJiyh^a (L.). This is the most puzzling, variable shell in the genus. Many species have been made out of it. They all run so nearly into each other as to merge into varieties. The type is grey or brown, white pustulated all over with small excrescent granules, extremities reddish brown tipped, teeth extended across the base on each side in ridges, sometimes yellow, sometimes white. Very variable in size, '5 to "lo inch normally, but I have a specimen 1*25 inch. {(i) interstificta (Wood). A form with pustules semi- obliterated, sometimes larger, teeth coarser and darker. (^b) liinacina (Lamk.). Smooth, oblong, white spotted,, teeth not extending across the centre of the columellar base^ very near the last var., but the pustules quite undeveloped. I have this also pellucid from the Sandwich Isles. Colour pale straw. A sub-species, as in the next. (f) polita (Roberts). A shorter, more brilliantly coloured pellucid shell from the Sandwich Isles, the minute white spots often obsolete except laterally, base white, teeth much as in small specimen of limacina. I do not know C. AnncB (Roberts), but suspect it to be a variety of this protean sub- species. [ii^ consobrina (Garr.). Mr. Andrew Garrett {J. of Couch. , 1879, p. 1 22) has likewise described Trivia [Pustular ia) conso- brina, which he separates from T. stapJiyla^a, the base being yellowish white instead of livid, and the teeth being mar- gined with yellowish brown, hair like lines, extending quite across the face of the shell, and being more or less bifid ; supplementary ones also may be observed between the primary teeth, which more or less anastomose towards the outer margins of the shell. Length 22 mm. Found rarely at the Viti and Samoa Islands, in dead, but perfect con- dition. Genus Cypma. 233 (c) seniiplota (Mighels), 1848. fiinbriatu la (Sowh.), 1870. Undoubtedly synonyms. I have two specimens labelled by the latter name, in no way excepting in small size (-4 inch) differing from the smooth white spotted liviacina (Lamk.). As Mr. Roberts suggests (Man. Conch. Cyp., p. 194) C. spadix (Mighels) is the immature state of this variety. The smaller Trivice have been so satisfactorily worked out by various eminent Conchologists, especially Gray and Gaskoin, as to be now almost perfectly systema- tized. As a rule they are fairly constant ; and their differentiation is not a matter of undue difficulty, if the presence or absence of the dorsal impression or sinus, and the colour, quality and quantity of ribs, and disposition of marking be regarded. ***** Lastly, with respect to the other species and varieties of Cyprcea proper, e.g. the cerviis and hiriindo sections, xantJio- don^picta and allies, and others, complete acquiescence in, and acceptance of the diagnoses in Sowerby's " Thesaurus Conchyliorum " must be taken as valid reasons against the necessity of further alluding to them in this paper. (XIV.) Doubtful species. C. cxiiiiia (Gray), Proc. Zool. Soc., 1849, is a fossil from Tasmania, very near C. ttmbilicata (Sowb.) It was supposed by Dr. J. E. Gray, the describer, to have become only recently extinct, after the fashion of Btdhmis aiiris-vidpiiia (Chemnitz) from S. Helena,* which, if one can compare the causes which lead to the annihilation of a marine form with those affecting a terrestrial species, seems to have been of equally restricted range, and to have eventually died a natural death. a Cf. Wollaston, Testacea Atlantica, p. 547. INIelliss. S. Helena, p. 121. pi. xxii., f. 2, 2^. 234 Mr. Cosmo Melvill on the C. GalathcecB (Reinhardt). Pet J., 1872, p. 326. Of this I know nothing. C. Jenningsia (Perry). Conch., pi. xix., f. 4. The following is Perry's description :— Shell of a beautiful pink colour, spotted with varied spots of a white colour, mouth paler pink, furbelowed and undulated ; two dark brown spots at each end. Unique in the cabinet of Mr. Jennings, of Chelsea. The figure does not represent C. guttata (Gray), with which some writers have supposed it identical, any more than the description. It is most likely a large and highly coloured variety of C. stapJiylcea (L.). Brief descriptions will also be found in Tryon. Man. Conch. Cyp., p. 207, of three unrecognised species. C. castanea (Anderson). C.parvida (Phil.). " ^Qd.r fimbriata;' C. trigonella (Dufresne). * * * * * (XV.) Eimmeration of Museums, etc., considted. In preparing this survey of the genus, for which I have been collecting material during the last eighteen years, besides utilizing my own specimens as much as possible, I have on many occasions been carefully through all the vast stores in the National Collection, South Kensington, where Mr. Edgar A. Smith, of the Zoological Department, and his assistant, Mr. Atkinson, have always been ready with kind help. Frequent visits have been paid to the Museum, Owens College, Manchester, where, in company with Mr. J. R. Hardy, the curator, I have thoroughly examined, classified and arranged the series of Cypnea, formed by the united collections of Mr. Swainson, Mr. Walton, and Mr. Cholmondeley. This contains some very interesting forms. At Peel Park Museum, Salford, through the courtesy of Mr. Plant, P'.G.S., the Lincolne collection, Genus Cyprcsa. 235 mainly acquired in 1825 at the sale of the celebrated Cabinet of Lord Tankerville, has been investigated. I have also often visited the Liverpool Museum, where the Rev. H. H. Higgins, Mr. T. J. Moore, and especially Mr. F. P. Marrat, have laid me under much obligation. The well selected collection of cowries, belonging to Mr. J. Michael Williams of the same city, have also been inspected with much pleasure and profit ; and last, but not least, Mr. G. B. Sowerby, of Fulham Road, London, has rendered me much assistance, and to him and all the above-named I would return most cordial thanks. As opportunity offered, I have likewise inspected the Natural History Museums in Paris, Brussels, Geneva, and some other Continental cities and towns ; and, in the United States, the Academies of Natural Science at New York, Boston, the Smithsonian Institution, Washington, and portion of the Philadelphian Academy Collections, on which Mr. Tryon bases his volumes ; also that of Montreal, Canada. The fine series of Australian Mollusca, collected and exhibited by Dr. J. C. Cox, of Sydney, at the Indian and Colonial Exhibition in London, during 1886, was also twice attentively examined. The works of Messrs. Sowerby, Reeve, and Adams, and the monograph of Cyprcea in Tryon's Manual of Con- chology, by Mr. S. Raymond Roberts, have all proved of the greatest service, and I also beg to tender my acknow- ledgements for the aid afforded thereby. 236 Genus Cyprcea. ADDENDUM. C. ocellata (L.). [b) calopJithalnia (van nov.). Shell oblong, dorsal surface pale yellow-ochreous, eyes remarkably large and prominently painted, twice the size of the ordinary ocelli ; the base with usual markings, as in the type, but of darker brown. Figured by Sowerby, Thes. Conch., pi. xxvi., fig. 243, from the specimen till lately in the possession of the late Mr. Walton, but now incorporated with the Owens College collection, Manchester, which is the only example I have ever seen. This and the var. {a) present the two opposite extremes in coloration-development of C. ocellata (L.). Long. \yi inch. A remarkably beautiful shell. Habitat : Ceylon. Mention of this was, by an oversight, omitted in its proper place. E R R ATA. p. 226, 1. 14, for ' this ' read * the.' „ 22, for ' liked ' read ' like.' p, 195, for 'mascarus* read ' mascarene/ p. 214, 1. 21, for ' iV ' read ' ^ ' inch. Describcrs of Cyprcca, 237 (XVI.) LIST OF THE DESCRIBERS OF RECENT SPECIES AND VARIETIES OF THE GENUS CYPR^A. Adams, H. & A. Ad ANSON, M. Ancev. Anderson. Angas G. F. Barnes. Beck, H. Bernardi, a. C. Blainville, H. M. D. de. Born, J. Brazier, J. Brocchi, G. Broderip, W. J. BUCQUOY, E. Chemnitz, J. H. Costa, O. G. Cox, J. C. Crosse, H. Dautzenburg, p. Deshayes, G. p. Dillwyn, L. W. DucLOS, P. L. Dufresne. Dunker, W. Fischer, P. Garrett, A. Gaskoin, J. S. Gill. Gmelin. Gray, J. E. Gronovius. HiGGINS, E. T. Humphrey, G. Jousseaume, F. KlENER, L. C. Klein, J. Lamarck, J. B. de. Leathes, G. LiNN/Eus, Carl. LOCARD, A. Macgillivray. Marie. Marrat, F. p. Martens, E. von. Martini, F. H. W. Martyn. Mawe. Melvill, J. C. Menke, C. T. Meusch. Mighels, J. W. Montagu, Colonel. MONTROUZIER. MORCH, O. A. Olivi, G. Owen, Hugh. Paetel, F. Pease, W. Harper. Perry, G. Petit, de la Saus. saye S. Philippi, R. a. Pulteney. QUOY. Reeve, Lovell. Reinhardt, O. Requien, E. Risso, A. Roberts, S. R. RocHBRUNE, A. de. ROSSITER, R. RuMPHius, G. E. Salis-Marschlins, C. U. von. Sars M. Shaw. Smith, Edgar A. Solander, Dr. souverbie. Sowerby, G. B. (sen.) SOWERBY, G. B. Sowerby, G. B. (jun.) swainson, w. Tapparone Canefri, C. Troschel, F. H. Tryon, G. W. (jun.) Weinkauff, H. C. Wood, W. 238 Catalogue of Cypnea. (XVI I.) A CATALOGUE OF THE SPECIES AND VARIETIES OF CYPRiEA [Linn. 1740— 1767], Arranged on a new circular system, in accordance with true sequence of affinity, By JAMES COSMO MELVILL, M.A.. F.L.S. Syn. Porcellana (Rumphius), Erythrsea (Barrol), Peribolus (Adanson), 1705. 1714. 1787. Cypriarius (Dum.), Cyprea(Montf.).Trivia(Gray), Cypraeovula (Gray), 1806. 1810. 1824. 1824. Naria (Gray), Aricia (Gray), Luponia (Gray), Cyprcedia (Swainson), 1828. 1832. 1832. 1840. Pustularia (Swainson), Epona (H. & A. Adams), Gaskoinia (Roberts). 1840. 1858. 1869. 1. C. Valentia (Perry), 1811. Syn. C. princeps (Gray). Zool. Persian Gulf. Jour. I, 75, 1824. N.Guin.(Cox). 2. C. viappa (Linn.) Syst. Nat. (12 Ed.), alga Perry, 181 1. East Indies and 1767. montosaRumph., 1705. Pacific Isles. a. panerythra (Melv.) 1888, cf. Sowb., Thes. Conch., f. 28. N. Caledonia. b. subsignata (Melv.) ,, „ ,, f. 24, 25, 27. St. Brandon Shoals, &c., Paumotus Is. (Garrett). c. nigricans (Montr.) 1875. J- ^^ Conch, p. 220, pi. 8, f. 5. N. Caledonia. 3. C. aurantut7n (Mzxi.), 1782. Aurora (Solander), 1795. Tahiti, Friendly Aurora Solandri (Chemn.), Isles, Loyalty 1795. Isles. 4- C. Broderipii (Gray). Descriptive Catalogue, 1832, p. 3. Madagascar. 5. C. nivosa (Brod.). Zool. Jour. III., p. 84. IMauritius. Salita (Rumph.), 1705. 6. C. vitelhis (L.), Syst. Nat. (12 Ed.), 1767. dania (Humph.), 1779. Eastern Seas, a. sarcodes (Melv.), 1888. subfuscula (Martyn), 1782. from E.Africa dama (Perry), 1811. to Japan and Australia, Pa- cific Isles. 7. (\ camelopardalis {Vt^xxy), \%\\. nielanostoma(Leathes), 1S25. Red Sea. Catalogue of Cypnca. C. pantherina (Solander). Dillwyn Cat. Shells, \'., p. 449, 181 7. MSvS. vinosa (Cimelin), 1790. flammea(Gmel.) 1790JUV. guttata (Lam.), 18 10. obtusa (Perry), 181 1. tigrina (Lamk.) 1822. a. hadionitens (Melv.), 1888. /'. theriaca (Melv.). ,, (/■. Sowb. , Thes. C(^nch. , pi. ii,f. 71. c. albonitens (Melv.), ,, d. juvenca (Melv,), ,, e. syringa (Melv.), ,, ■39 Red Sea, C. tigris (L. ) Syst. Nat. (12 YA. ),p. 1 1 76, 1767, leopardalis (Humph.), 1779. guttata (Rumphius), 1 705. tigrina (Gniel.), 1790. pardalis (Shaw), feminea (Gmelin), 1790. ambigua (Gmelin), 1790 juv. a. flavonitens (^relv.), 18S8. h. hinnulea (^lelv.) ,, c. russonitens (Melv.) ,, d. chionia (Melv.) ,, e. ionthodes (Melv.) ,, f. lyncichroa (Melv.) ,, q. zymecrasta (Melv.) ,, grummuhis (Humph.) 1779. C siercoraria {\Ar\x\.). Syst. Nat. p. 1 174, cauteriata (Chem.), 1788. 1767. fasciata(Chem.), 1788, testa juv, ? olivacea (Gmel.) 1790, nebulosa (Gmel.) 1790. conspurcata (Gm.), 1790, a. gibba (Gmel.), 1790, b. rattus (Lamk.), 1822. Thatcheri (Cox) 1869. roseopunctata Sb. MSS. C. venusta (Sowb.), Ann. Mag. N, H. XIX., p. 346, 1847. C. umbilicata (Sowb.). Tank. Cat. p, 30, f. 7, 1825. a. alba (Cox). C. Scottii (Broderip). Zool. Jour. V., 330, 1831. Friendii ((iray) 1832. C. inarginata (Gaskoin). Zool, Proc. 1848, p. 91. an, van, juv. sqq. ? C. Thersiies (Gaskoin). Zool. Proc. 1848, p. 90. C. decipiens (E. A. Smith). Zool. Proc. p. 482, pi, 48, 1880. C. nnis (Linn.). Syst. Xat, p. 1176, 1767, autumnalis (Perry) 181 1. a. bicornis (Sowb.). Thes. Conch, pi, 30, f. 321, 1870. C. kucostoina (Gask.). Zool. Proc. p. 25, f. 1843 All Eastern Seas, rare at More- ton Bay, Aus- tralia(Coxen). Fiji Isles and Mauritius. Caroline Isles, (Garrett), &c. "West Africa. Dampiers Island W. Australia. X, S. Wales. Tasmania, Swan River, W, Australia. South Australia. South Australia. Xorth and West Australia, Mediterranean, Canary Islands Arabian Seas. 240 Catalogue of Cyprcca, [9. C". vioueta (L.). Syst. Nat. p. I178, 1767, cx-rulea (Perry) iSii. a. icterina (Lam.), 1822. b. Barthelemyi (Born.), 1861. c. atava (Rochbrune), 1884.* d. camelorum (Rochbr.), 1884. e. ethnographica (Rochbr.), 1884. f. mercatorum (Rochbr.), 1884. }i: pleuronectes (Rochbr.), 1S84. //. phmiaria (Rochbr.), 1884. i. vestimenti (Rochbr.), 18S4. 20. C. ohvallata (Lam.) (obvelata) An. sans. Vert. VIL, 1822, a. calcarata (Melv.), 1888. 21. C. a ?i fmhis {L,mn.). Syst. Nat., p. 1179, annularis (Perry), 181 1. 1767. a. Noumeensis (Marie), 1884. />. Hamyi (Rochbr.), 1884. c. Harmandiana (Rochbr.), 1884. d. Rerrieri (Rochbr.), 1884. e. pura (Paetel Cat.), 1887. 22. C. caput, angiiis (Phil.). Menke and Pfr., p. 24, 1849. reticulum (Gmel.), 1790. 2j. C. caput serpcntis (L.). Syst. Nat., p. 1 175, 1767. albella (Lam.), 1822. 24. C. caput draconis (Melvill), 18SS. I\L and P. Manch. Lit. and Phil. 80c., 4th Ser., Vol. I., p. 214. undata (Chem.), 1767. Bulla Cypra^a (Gmel.), 1790J1 regina (Gmel.), 1790 juv. 25. C. MaiD-itiajiaiX'^nVi.). Syst. Nat., p. 1 176. turbinata (Gmelin), 1790. 1767. trifasciata(Gmel.), 1790 juv. fuliginosa (Perry), 181 1 juv. 26. C. Arahica {\^.). Syst. Nat., p. 1173, fragilis (L.), 1767 juv. 1767. amethystea (L.), 1767. bandata (Perry), 181 1 juv. a. reticulata (Martyn), 1782. /'. histrio (Meusch), sp. 1787. ■c. intermedia (Gray), 1824. d. eglantina (Duclos), 1883. e. niger (Roberts), 1885. maculata (Barnes), 1S24. arlequina (Chemn.), 1790. Laccadives and Maldives, In- dia, Ceylon, Philippines, E. Indies, Java, China, Japan, Australia. jj New Caledonia. India. W. Africa. E. Indies. Corsica ? Maldive Isles. Sandwich Isles. N. Caledonia. E. Indies, Cook, Society, and Paumotus Is. (Garrett). ,, and Australia. New Caledonia. Zanzil)ar. Mauritius. Australia? Sand- wich Isles ? Sandwich Isles, Australia, India, Pacific. I long Kong. Mauritius, Bor- neo, Ceylon, Pacific Is., >!\:c. India, Pacific Islands, East Indies, Formosa (Swinhoe). India & Pacific. E. Indies. Paumotus, Cook Isles, &c. New Caledonia. a Cf. de Rochbrune, Monograpliie de Gen. Mcrcatoria, lUilletin Soc. Malacog. de France, i334, where all these mere varieties are treated as of specific importance. Catalogue of Cj'pnra. 27. (7.j«/rra(Chemn.),Conch.Cat. X.,p. 103, indica (Gmel.), 1790. 178S. 28. C. genwmla (Weinkauft"), iSSi. 29. C. Arabiada (Lam.). An. Sans. Vert. VII., 1822. 30. C. pimciitlata (Gray). Zool. Jour. L, p. 387, 1824. 31. C/a//zV/a (Gray). Zool. Jour. I., p. 387, 1824. 32. C.xantJiodon (Gray). Descr. Cat., p. lo, 1832. 33. C. nioropjuictata{^x'xy). Zool. Journ. IV., p. 81, 182S. a. irina (Kiener).* 34. C. lentiglnosa (Gray). Zool. Journ. I., p. 489, 1824. maculata (Gray), 1824. 35. C.c^;/a/'a(Chemn.). Conch. Cat. X., 1788. Zonaria (Gmel.), 1788. a. Surinamensis (Perry),^ 1811. nebulosa (Kiener), 1S40. 36. C. sangziinolenta (Gmel.). Syst. Nat., purpurascens (Swn.), 1823. 1790. purpurata (Solander), 1S17. 37. C. picta (Gray). Zool. Jour. I., p. 389, pi. 7, 12, f. 10, 1824. 38. C. suhviridis (Reeve). Proc. Zool. Soc, 1835. ovata (Gmel.), 1790. ovum (Gmel.), 1790. subflava (Gmel.), 1 790. 39. C.erronesiX")- Syst. Nat., p. 1 178, 1767. oblonga (Gmel.), 1790. erronea (Gmel.), 1790. olivacea (Lam.), 1822. a. chrysophrea (Melv.) 1888, h. Coxi (Brazier). Zool. Proc, 1873, sp. c. Sophios (Brazier). Proc. L. S. N. S. W., I. p. 7, 1875, sp. chrysostoma (Brazier), 1880. 40. C, cylindrica (Born). Mus. p. 184, 1780. punctulata (Gmel.) 1790. a. subcylindrica (Sowb.) Thes. Conch., Cyp., pi. 27, f. 269, 270, 1870. 41. C.hirundo (Linn.). Syst. Nat., p. I178, 1787. a. Rouxi (Ancey), Le Nat. No. 7, p. 55, 1882. ^ The variety irina I take to be the larger form of the species. 1> If the reported Gulf of Mexico habitat for this sub-species be not confirmed, it would be wise to abandon the rame Surifiamensis, and revert again to that bestowed by Kiener. J4I Indian Ocean and Pacific Is. Red Sea. Mexico, Lower California. Panama, Lower California. Hong Kong, East Indies. Australia. Gallapagos Isles Ceylon. Senegambia, W. W. Africa. West Indies ? Gambia. Gambia. Cape de Verde Isles and adja- cent coast, W. Africa. Australia and N. Caledonia. Indian &Chinese Seas, Australia, and Pacific Is. Port Blair, An- daman Isles. Dupuch Island, N.W.Australia, San Christoval Island, Solo- mon Is. Ceylon, Phili].- pines, Japan, Mauritius. Ceylon, New Caledonia, Philippines. New Caledonia, Ceylon, Aus- tralia. 242 Catalogue of Cyprcea. 42. C. fclitia (Gmel.) vSyst. Nat., p. 3412, 1790. a. ursellus (Gmel.). Syst. Nat., p. 341 1, 1790. 43. C. fahiila (Kiener). Coq. Viv., p. 54, an. var. prxc. ? Sowerbyi (Gray), 1832. 44. C, ncgieda (Sowb.). Conch. 111., sp. 66, 1837. 45. C. coffea (Sowb.). Thes. Conch.. Cyp. pi. 32, 1870. 46. C. CTc'^;^//(Sowb.). Conch. 111., sp. 64, 1837. 47. C. Menkeana (Desh.). Conch. I. Reunion, 1863, an. var. pr?ec. ? a. modesta (H. Owen), 1870, cf. Sow])., T. C, f. 512. 48. C. finihriata {Qm*i\.). Syst. Nat., p. 3420, 1790. a. microdon (Gray). Zool. Jour., 1828, sp. h. unifasciata (Mighels). Proc. Bost. Soc. II., p. 25, 1848, sp. c. macula (Adams), 1867. ut sp. notata (Gill), 1858. an. nom. vetust. rest ? irescens (Sowb.), 1870. d. Cholmondeleyi (Melv.), 1888, cf. Sowb., T. C, pi. 32, f. 387, 388. 49. C. irrorata (Solander). NARIA i. (Gray), 1828. 50. C. qiiadi-imacidata (Gray). Zool. Jour. I., p. 376, 1824. a. pallidula (Gaskoin). Zool. Proc, 1848. 51. G. intemipta (Gray). Zool. Jour. I., p. 77, 1824. a. rhinoceros (Souv.). J. de Conch., p. 156, 1865. 52. C. Rashkighana (Melvill). Jour, of Conch. V., p. 288, 1887. 53. C. /^;rj- (Gmel.). Syst. Nat., p. 3405, .subteres (Weink.). 1790. cylindrica (Wood), 1S28. 54. C. iahescens {^^vAziXKiXQix). Dillwyn Cat. I., (teres Gmel.?) 1817. in jmrt. a. latior (Melv.) 1888, cf. Reeve, Conch. lom. XIV., 66a, 1845. b. pellucens (Melv.) 1888. c. alveolus (Tapparone Canefri), J. de Conch. XXX., p. 30. d. elaiodes(Melv.) 1888. Indian Ocean and Pacific Is. Australia, India. Borneo. Mauritius. I. Reunion, Borneo. I. Diego Garcia, Seychellas. Japan, Paumo- tus, and other Pacific Isles, Australia. Mauritius, Cey- lon, Fiji Is., &c. Sandwich and Society Isles (Garrett). Japan and Aus- tralia. Australia. PaumotusArchi- pelago, Society and Cook's Is. East Indies, Fiji Isles (Garrett) ? Ceylon. New Caledonia, P'iji&Samoal. Ceylon, Society and Paumotus Is. (Garrett). N. Caledonia. Tropical Aus- tralia, East Indies,Pacitic. Sandwich Isles. Mauritius. Catalogue of Cyprcsa. 243 55. C, caurica (Linn.). Syst. Nat., p. 1767. a. oblongata (Melv.), 1888. dentex (Humph.), 1779. 179, dracKna (Born), 1780. corrosa (Gron.), 1783. stolida (Gmel.), 1790. derosa (Gmel.), 1790. elongata (Perry), 181 r. b. concava (Hugh Owen), 1870. c. obscura (Rossiter). 56. C. crtienta (Gmelin). Syst. Nat., p. 3420, morbillosa (Sol,), 1817. 1790. variolaria (Lam.), 1822. cruentata (anct. var.). a. coloba (Melvill), 1888. 57. C. stolida (L. ). Syst. Nat., p. 1180, 1767. rubiginosa (Gmelin), 1790. a. moniontha (Melv.), 1888. h. diauges (Melv.), 1888. c. gelasima (Melv.) 1888. d. Crossei (Marie), 1884. hrevidentata (SowId.), sp. Thes. Conch., 1870. an. var. preec. ? Erythrivensis (Beck). Reeve, Conch. Icon., pi. 14, f, d^^^ 1845. Barclay i {K(t&\Q.). Zool. Proc, p. 208, pi. 38, f, 4, 1857. piilchella (Swn.). Phil. Mag. 61, p. yj6, 1823. pyriforin/s (Gray). Zool. Journ. I., p. 371, 1824. 58. c. 59. c. 60. c. 61. c. 62. a ^^.^ a 64. a a. Smithi (Sowb.), Zool. Proc, 1881, pi. 56, f. 8. Bregeriana (Crosse),* 1868. J. de Conch. XVL, p. Walkeri (Gray). Desc. Cat., p. 10, 1832. 277. a. amabilis (Jousseaume), 1881. chinensis (Gmel.), 1790. leucostoma (Gmel.), 1790. squalina (Gmel.), 1790. 65. C!. lynx {\^.). Syst. Nat., p. 117^, 1767. Vanelli (L.), 1767, test. juv. a. Caledonica (Crosse), 1869. h. Williamsi (Melv.), 1888. -66. G. .Sa/z/^t? (Gaskoin). Zool. Proc, p. 23, 1843. 67. C. gracilis (Gaskoin). Zool. Proc, p. 93, \\ E.Indies, Pacific Isles, Australia (Coxen). EastIndies,Hin- dostan,Ceylon, Australia. Mauritius. New Caledonia. E.Indies, Pacific Is.rare(Garrett) Ceylon, Borneo, Philippines, Fiji. Mauritius. New Caledonia. Borneo. Red Sea to Zanzibar. San Diego, I. Mauritius. China Seas. Ceylon, N. Aus- tralia. New Caledonia. Philippines, New Guinea(Braz.). G. of vSuez, Na- tal, Australia, Eastern Seas, all Pacific Is., India, &c. N. Caledonia. N. Borneo. Philippines. El- phinstone Is. (Chall.Exped), Peel L, More- ton Bay (Braz.). I. Bourbon, China Seas, (Samarang Voyage). a Although usually attributed a variety of Walkeri, perhaps Weinkauff and Paetel are correct in assij;iiing -pecific rank to this shell. As previously observed, a form nearly allied to this will shortly be described by Mr. >:. A. Smith, from N. W. Australia. 244 Catalogue of Cyprcua. 68. C. Goodalli (Gray). Descrip. Cat. Cyp. 1832. a. fuscomaculata (Pease). Zool. Proc, 1865. 69. C. Addimr (Roberts). fuscomaculata (Gray), 1870. 70. C. coufaminata (Gray). Descrip. Cat., Cypnxa, 1832. 71. C. puuctafad..). Mantissa, p. 548, 1771. atomaria (Gmel.), 1790. a. stercus muscarum (Lam.), 1822. /'. trizonata (Sowb.), 1880. 72. C.dandestina{i:mx\.). Syst. Nat., p. 11 77, pusilla (Gmel.), 1790. 1767? moniliaris (Lam.), 1822. a. Candida (Pease), Zool, Proc, 1865. lb. Artuffeli (Jousseaume). Bull. Soc. Zool., France, 1876. c, passerina (Melv.), 1888. d. aberrans (Ancey), Le Nat., 1882. ^Z• C. asellus {!..). Syst. Nat., p. 117S, vespa (Rees, Cycl). 1767. 74. C. dilHciilum (Reeve).' Conch. Icon. undata (Lam.), in part, XIV. 65, 1845. 1822. ziczac (Dillwyn). 75. C. ziczac {!..). Syst. Nat., p. 1 177, undulata (Wood), 1828. 1767- misella (Perry), 1811. lineata (Gmel.), 1790. 76. C lutca (Gronov.). Zoophyl. fascic. 3, nivea (Mawe), 1828. pi. 19, 1781. commixta (Mawe), 1828. a. Humphreysii (Gray). Zool. Journ. I., 1824. 77. C. CoDiptojil {QxTiy). Jukes' Voy. II., p. 356, 1847. 78. C. angustata (Gmel. ) . Syst. Nat. , p. 342 1 . maculata (Perry) , 1 8 1 1 . 1790. 79- C. ^/c6//w>(Sowb.). Thes. Conch. III., 1870. 80. C. piperita (Solander). Zool. Journ. I., p. 498, 1824 (Gray). a. bicolor (Gaskoin), Zool. Proc, 1848. Lord Hood's Is. I. Apaian, Plji, Tonga Isles^ Pacific ? E. Ind. Islands. Philippines, Pacific Isles. Ceylon, PacificL Australia. ? ? ? ? Australia, Fiji, and E. Indies. Mauritius, Bour- bon, Philip- pine Isles. Ceylon, Mozam- bique, West Africa. N. S. Wales. L. Macquarie (Angas, Brazier). S. Australia. S. Australia and Tasmania. Victoria, Australia. Australia. Australia and Sandwichlsles. (Mus. Brit.). Australia. Algoa Bay, S. Africa. C. G. H. 81. C. piilicaria (Reeve). Zool. Proc, p. 23, 1846. ^2. C. ede7itnla{^o\\\\). CI. Ills. sp. 102, Gaskoiniaedentula(Roberts). C. G. H. 1837. 83. C\ Algoensis (Gray). Zool. Journ. I., p. 498, 1824. 84. C. si7nilis (Gray). Zool. Miscell., p. 26, 1844. a. castanea (Higgins). Zool. Proc, p. 78, 1868, sp. 85. C. ftiscodenfata (Gray). Zool. Jour. I., p. 499, 1S64. ^6. C. amphithales (MelviU), 1888. M. and P. Manch. Lit. and Phil. Soc. 4th Series, Vol I., p. 221. ^1. C. Capensis (Gray) [Cvpr/EOVULA]. Zool. Jour. III., p. 573, 1828. %%. C. Adamsojzii [Gx^iy). Desc. Cat. Cyp., p. 7, 1832. Port Elizabeth, S. Africa. C. G. H. I. Capul, Philip- pines, Tahiti, Society & Pau- motusI.,Pacif. » Mr. T.oyell Reeve's reasons for altering the name i<7idata to diluculum may Ije found in his Conch. Icon. The former title was first given to another species, in part only, and confused by Linnjeus, thus necessitating the suppression of the T,amarckian name. Catalogue of Cypnca, 245 [Subgen. TRIVIA (Gray), sp. 89—140.] o\\h.). C. 111., sp. 130, 1837. ■97. C. Maiigenc (Gray). Descr. Cat. Cyp., p. 13, 1832. 98. C. sa72gtiinea (Gray). Descr. Cat. Cyp., lathyrus (Dufresne), 1826, p. 14, 1832. 99. C. pisum (Gaskoin). Zool. Proc, p. 24, 1846. 100. C. pedicidiisiX-xnn.) Syst. Nat., p. 11 80, picturata (Morcli), 1877. 1767. sulcata (Dillwyn), 1887. a. labiosa (Gask.), 1835. /--. cimex (H. Owen), 1870. loi. C. /iT^jr^ (Gray). Desc. Cat., Cyp., p. 15, 1832. 102. C. siiffusa (Gray). Desc. Cat., Cyp., C. armandina (Duclos). p. 16, 1832. a. pullata (Hugh Owen), 1879. 103. C. Pacijica (Gray). Desc. Cat., Cyp., p. 15, 1S32. I'anama. Honolulu, Sand- wich Isles. Central Pacific (H .Pease). Philippine Isles, Pacific Isles, Mauritius, &c. St. Elena, West Columbia, Ecuador. Panama. California. Gallapagos Isles. California and S. American Coasts. Ceylon. Florida, West Indies. Gallapagos Isles West Indies. G. of California ros/7'a^a [Gray). Zool. Jour. III., p. 363, 1S27. 108. C. proditcta (Gaskoin). ZooL Troc. , 1835, p. 200. 1S48. 109. C. paucili7-ata (8o\vl). ) Thes. Ctnich., Cyp., No. 175*, 1S70. no. C. rubi7iicolor {G'^'^Vi^vlw). Zool. Proc, p. 200, 1835. 111. C. a^m's {Man-at.) Ann. Mag. N. H. XX., 1867. 112. C. rubescens {Gxa.y). Zool. Proc, p. 185, 1832. 113. Cy^rw^j-a; (Gaskoin). Zool. Proc, p. 198, 1835. a. multilirata (Sowb.), 1870. 114. C.Eiifopcca {'MoniTxgw). Test. Brit. Sui^p. , p. 88, 1808. pediculus (Mont.), 1803. a. arctica (Solander), 1803. I>. bullata (Pulteney), 1803. c. Candida (Gill), 1843. d. coccinella (Lamk.), 1822. e. diaphana (Montagu), 1808. f. globulosa (Wood), 1828. g. Mediterranea (Risso), 1826. //. Norvegica (Sars), 1845. /. sphcerica (Lam.), 1810. ;. sulcata (Dillwyn), 1817, an. C. pediculi forma? /•. umbilicaris (Costa), 1845. /. Jousseaumei (Locard), 1886. 115. C.N'apolmi{'D\\c\os). Coq. Mv. , p. 144, obscura (Gask.), 1848. Pl- 53, f- 3- 116. C. Aitsii-alis {Liim\i.) An. Sans. Vest, rosea (Duclos), 1838. VII., p. 404, 1822. 117. C /////a (Gaskoin). Zool. I'roc 1846, p. 24. 1848, ]>. 97. 118. C. /^/Au- (Solander). Zool. Jour. III., lachrymalis (Mk.), 1828. MSS. 1827. " rosea (Requien), 1 848. 119. C. onisciis (Lamk.) Ann. du Mus. apcrta (Swn.), 1828. XVL, p. 103, 1810. ,, (Mawc), 1835. 120. C. (7z^///a/a (Lamk.). Ann. Sans. Vest. \TI., p. 398, 1822. [21. C. z't'j-?'(7//a;7V (Gaskoin). Zool. Proc, p. 203, 1835. [22. C. costata{Gw\it\.). Syst. Nat., p. 3418, trilicea (Dufr.), 1826. 1790. carnea (Gray), 1828. rosea (Wood), 1828. [23. C j-?^/m/^ (Gaskoin). Zool, Proc, Gaskoinii (Roberts), 1869. p. 95, 1S4S. Bay of Guaya- quil, Ecuador. ^^'est Indies. Borneo, S.Africa, Australia. (Jeylon, Borneo. ? W. Indies. Ciallapagos Isles C. G. H. Adriatic Sea. Europe, Medn., Great Britain. European Seas. Cape de X'erde, Senegal, ^:c. S. Australia, Gallapagos Isles. Corsica (Sal is Schwabe), Meditn. Sea, Azores. C. G. H. „ ? and W. Indies (Krebs sec Rol)erts). Philijipine Islds. 124. 125- 126. 127. 1 28. 129. no. Catalogue of Cypnca. C. vitrca (Gaskoin). Zool. Proc, p. 95, 1848. C. glolwsa{{^x'^y). Descr. Cat. Cyp., pilula (Kiener). 1840. p. 14, 1832. sphrerula (Mighels), 1848. C. candiditla (Gaskoin). Zool. Proc, approximans (Beck), 1835. p. 200, 1835. olorina (Dados), 1835. C. brevissima (Sowb.). Thes. Conch, Cyp., No. 168, 1870. C. pelhicidida (Gaskoin). Zool. Proc, p. 23, 1846. C. itivea (Gray). Desc Cat. Cyp., scabriuscula (Kiener), 1S40. p. 15, 1832. C ^;j:i^(Lamk.). Ann. du Mus. XVI., pediculus (L.) in part., p. 104, 1810. 1767. 131. C ^r^/z^/t? (Gaskoin). Zool. Proc, p. 96, 1S48. hordacea (Kiener), 1S40. 132. C. insecta (Mighels). Proc. Bost. Soc II., p. 24, 1845. 133. C. cicatrosa (Sowb.). Thes. Conch., No. 160, 1870. 134. C. scabj'iuscula {GxTiy). Zool. Jour. IV., intermedia (Kien.), 1840. p. 1827. Sand\vichensis(Sowb.), 1870. 135. C. margarita (Sol. MSS.). Zool. Jour. IV., p. '^'j, 1828. 136. C. anmUata (Gray). Zool. Jour. I\'., p. 88, 1829. 137. C. Childreni [Gx^iy). Zool. Jour. I., p. 51S, 1824. ' C. affinis (Gmel. ), 1790. 138. C. globulus (L,). Syst. Nat., j). 1161, 1767. 139. C. cicerciila (L. ). Sys. Nat., p. I181, 1767. a. Lienardi (Jouss.), 1874. /'. tricornis (Jouss.), 1874. 140. C. slaJ^hylcmiX'.). Syst. Nat., j). 1181, granulata (Humph.), 1779. 1797- striata (Gmelin), 1790. a. interstincta (Wood), 182S. Jenningsia (Perry), 181 1 ? l>. limacina (Lamk.), 1822. c. polita (Roberts), 1868. d. consobrina (Garrett), 1879. e. semiplota (Mighels), 1848. Annx (Roberts), 1868. fimbriatula (Sowb.)., 1870. Spadix (Mighels), 184S. 247 Philippines. W. Indies, Aus- tralia, Sand- wich Isles, So- ciety and I\au- motus Isles. E. Atlantic. Mexico. Pacific Ocean, West Indies. Sandwich Isles. Philippines. Society Isles (Garrett), Manila, Philip- pines. Sandwich and Pacific Isles, Australia. ? E. Indies. Annaa I. , Society and Paumotus Isles, South Pacific Ocean. Mauritius and Philippine Is. , Fiji, Pacific Is. Borneo, Philip- pines, N. Cale- donia, Pacific, Mauritius, Bor- neOjNewCale- donia. Pacific Isles. Borneo. Mauritius. E. Indies, all Pacific Islds. Pacific Islands. E. Indies, Fiji, Samoa I. Sandwich Isles. Fiji and Samoa. Sandwich Isles. J48 Catalogue of Cypnca. chalcedonia (Perry), iSli. citrina (Kien. )> 1840. derosa (Risso. ) 141. C.helvola{la.) Syst. Nat.,]). 1180, 1767. stellata (Humph.), 1779. albella (Lam.), 1S22, a. Mascarena (Melv.) 1888. h. argella (Melv.), 1888. c. Hawaiiensis (Melv.), 1888, cf. Sowb., T. C, pi. 25, f. 217. 142. C. citrina (Gray). Zool. Jour. I., p. 509, 1824. 143. (7. Thoiiiasi {Qxo'~>uf dracom's (Melvill). 2, 2\ C. caput serpe7itis (L.). 3. C. Rashleighana (Melvill). 4. C. stolida (L.) var. vioniontha. 5. Do, var. diauges. 6. C. miliar is (L.) var. viagistra, 7. C. cruenta (Gmel.) var. coloba. 8. C. caiirica (L.) var. oblongata. 9. Do. dwarf var. 10. C. erosa (L.) var. strainifiea. 11. -£>^. var. nebrites. 14. C ocellata (L.) var. palatJia. 15. C. fiinbriata (Gmel.) var. C/iolmondeleyi. 16. C. La7n arckii {Gr?iy) var. redimita. 17. C. guttata {Qjx:if). 18. C Helvola (L.) var. Haivaiiensis. 19. C ajHpkithales (Melvill). 20. C. Capensis (Gray). 21. C Algoensis (Gray). 4ih Series, Vol. I. CYPRCEA.— Plate I. iO 'VW 14 MEMOIRS AND PROCEEDINGS, MANCHESTER LIT. AND PHIL. SOC. 4th Series, Vol. I. CrPRCEA.— Plate 2. la A \ 1 16 0 f 19 \! 18 ) 21 MEMOIRS AND PROCEEDINGS, MANCHESTER LIT. AND PHIL. SOC. Balfour Stezuart. 253 Memoir of the late Professor Balfour Stewart, LL.D., F.R.S. By Professor A. Schuster, Ph.D., F.R.S., F.R.A.S. {Received April 2j, 1888). Balfour Stewart was born on November ist, 1828. He went to school at Dundee, but entered St. Andrews University at the age of thirteen, and from there passed on to Edinburgh, where he studied under Professor Forbes. Leaving College when he was eighteen years old he was sent by his parents to serve his apprenticeship in business with a firm at Leith,and afterwards went out to Australia with a cousin, James Balfour, to start on a commercial career. But he was never fond of business and soon returned home to Edinburgh, where he became assistant to Prof Forbes in 1853. In 1859 he was appointed Director of the Kew Observatory, and held this post until 1870, when he was appointed Professor of Physics at the Owens College, Manchester. He died of apoplexy, on December 19th, 1887, at Ballymagarvey, near Drogheda, where he had gone to spend the Christmas holidays. Balfour Stewart's name was first prominently brought before the public by his researches on Radiant Heat. His paper was presented to the Royal Society of Edinburgh, and read on March loth, 1858. Stewart's claim, as one of the founders of the theoretical basis of spectrum analysis, rests on the experiments and reasoning contained in this paper. To appreciate the work done by Stewart we must realise what was known and generally recognised at the time his experiments were made. Those interested in the subject will find an account of the early history of Prevost's theory of exchanges by Stewart 254 Dr. Scpiuster 07i himself, in the Reports of the British Association for 1861. In this report he summarises the results of his own experi- ments as follows. 1. The radiating power of thin polished plates of dif- ferent substances was found to vary as their absorptive power, so that the radiation of a plate of rock salt was only 15 per cent of the total lampblack radiation for the same temperature. 2. It was shown that the radiation from thick plates of diathermanous substance is greater than that from thin plates, no such difference being manifested when the sub- stances are athermanous. 3. It was found that heat, radiated by a thin diather- manous plate, is less transmissible through a screen of the same material as the heated plate than ordinary or lampblack heat, this difference being very marked in the case of rock salt. 4. Lastly, heat from a thick diathermanous plate is more easily transmitted through a screen of the same nature as the source of heat than that from a thin plate. The conclusions drawn from these experiments are now generally recognised. Kirchhoff, somewhat later than Stewart, fully proved them from thermodynamical princi- ples, and gave a more definite meaning to the terms radia- tion and absorption. In view of the great importance, which now attaches to the science of Spectrum Analysis, a few words are necessary to explain the difference between Stewart's and Kirchhoff 's treatment. Stewart proved that the streams of radiant heat crossing any point of an enclosure of uniform temperature, are not altered by the interposition of a body whether opaque or transparent ; and this, as the author shows, is easily explained on the theory that, when equilibrium of temperature is established, any body or part of a body radiates as much heat as it gains. The radiation crossing any point is made up of heat which tJie late Balfoiw Stewart. o:> has passed through different thicknesses of the transparent bodies in various directions. What Stewart established for the sum of these streams, Kirchhoff proved for each of them individually. The reasoning thus becomes much more complicated, but the proof more complete and definite. In other words : Stewart had shown that the law of equality between radiation and absorption could explain all phenomena. Kirchhoff went further and proved that the law is the only one which can account for the facts. The existence of internal radiation was completely esta- blished by Stewart's researches, and he also considered the connexion between internal radiation and refractive indices. Considering the problem at first only as one of two dimen- sions, he took the internal radiation to be proportional to the refractive index, but later corrected the result and con- cluded, as was also done by Kirchhoff, that when three dimen- sions are taken into account, the intensity of internal radia- tion must vary as the square of the refractive index. Although Stewart generally speaks only of the sum of all thermal radiation, he shows that the laws he deduces must be true for each individual wave length. From this there was only one step to the complete generalisation of spectrum analysis. He has told the author of this notice, how he tried an experiment which was to lead him still further in the same direction. Salt was placed in a spirit flame and the yellow flame was looked through a plate of rock salt. Believing the yellow colour of the flame to be due to lumi- nous salt, he expected the rock salt to absorb an appreciable quantity of the light, which, however, was found not to be the case. We now know that salt is decomposed in the flame and that the yellow flame is due to luminous sodium vapour, which explains the failure of Stewart's experiment. In February, i860, Stewart communicated to the Royal 256 Dr. Schuster on Society of London a paper {Proc. Roy. Soc, X., p. 385) in which a number of experiments on radiant light were described. It was mentioned that the amount of light radiated by coloured glasses is in proportion to their depth of colour, transparent glass giving out very little light; also that the radiation from red glass has a greenish tint, while that from green glass has a reddish tint. It was also shown that when black and white porcelain is heated in the fire, the black parts give out much more light than the white, thereby producing a curious reversal of the pattern. In another paper {Proc. Roy. Soc. X.) an experiment was described showing that tourmaline, which absorbs the ordi- nary ray so that the transmitted light is polarised, radiates the same ray in excess when hot, but that when the heated tourmaline is viewed against an illuminated background of the same temperature as itself, this peculiarity disappears. The Proceedings of the Roy. Soc. (XL, p. 193) contain a short theoretical note on the internal radiation in uniaxial crystals, in which the different refractive indices in different directions are considered. Another important problem connected with the theory of radiation occupied Stewart's mind, and led to a joint experimental investigation with Professor P. G. Tait. When all bodies in an enclosure through which no heat is allowed to pass are at rest, we know that equilibrium of temperature establishes itself But this is no longer necessarily true when one of the bodies is in motion. A body whose par- ticles are vibrating in the same period will, when in rapid motion, appear to send out rays of different refrangibilities, according as it is viewed from the front or from behind. Similarly its absorptive properties will be altered. It is not quite easy to see what relations must hold between absorption and radiation, in order that a body may retain the same temperature whether at rest or in motion. Stewart and Tait tried to solve the problem by experiment, and the late Balfour Steivart. 257 published their results in three papers, "On the heating of a -disk by rapid rotation in vacuo." {Proc. Roy. Soc, XIV., p. 90 and 339 ; XV., p. 290). They have summed up the results of their experiments as follows : — r. There is a temporary heat or cold effect which may he supposed to arise in particles very slightly attached to the disk ; this is radiated off chiefly during rotation, and probably does not greatly affect the disk afterwards. 2. There is a surface gas effect, Avhich in an aluminium, and even in an ebonite disk, is conducted into the interior as it arises, so that it does not greatly radiate during rota- tion of the disk. In a paper disk, however, which is formed ■of a badly conducting material loosely put together, part of the effect does escape as radiation during rotation. 3. There is a residual effect which is more deeply seated than the gas effect. And in as much as radiation takes place from a perceptible depth, this effect is much more influential than the gas effect in increasing radiation after rotation. In the case of a paper disk, this deeply seated effect will be less diminished by radiation during rotation than the gas effect, and therefore after rotation in such a disk we might expect the gas effect to be peculiarly small. During the latter part of Stewart's life his attention was chiefly devoted to meteorology, terrestrial magnetism and solar physics. While at Kew, the important question of accurate temperature measurements presented itself, and rgave rise to a series of experiments on the air thermometer. The results are published in the Transactions of the Royal Society (Pliil Trans., i S6;^). A paper " On the melting point •of Paraffin," published in the Proce-edings of this Society (XII., 1873) originated in the want felt by him of a standard point of temperature between that of freezing and of boiling water. The subject of Terrestrial Magnetism is a great loser 258 Dr. Schuster 071 by Stewart's death. He felt the necessity not only of making observations, but also of reducing and discussing them. In a complicated subject like this, any discussion must be founded on some preliminary hypothesis which commends itself to the author's mind. Some writers in publishing their result, prefer to give only what they con- sider strictly proved, and to keep back the hypothesis which has served them as a stepping stone. But it is doubtful whether the method followed, for instance, by Faraday, in which the scientific public is taken into the author's con- fidence, and in which the author's train of thought is made clear, is not of greater ultimate advantage to science. It must always depend on the personal temperament of the author which of these methods he adopts, and Stewart preferred always to put forward what he called his "working hypothesis." His ideas on the nature of the forces w^hich produce magnetic disturbances have changed but little from the year 1 861 to the time of his death. The earth itself and earth currents only acted, in his opinion, in a secondary way, while the primary current producing the disturbance takes place in the upper regions of the atmosphere. He concludes his first paper on the subject {Proc. Roy. Soc. XI.) by putting forward the hypothesis that earth currents and auroras are due " to the fluctuating nature of this primary current " (by induction), while " the magnetic disturbances are due to its absolute intensity." The various facts which have come to light since 1862 have not materially altered in his opinion, except in so far that in his later writings he seems to ascribe a greater importance to earth currents in producing magnetic disturbances. In connexion with Mr. Sidgreaves, Stewart compared the simultaneous changes of declination during disturbances at Kew and Stonyhurst, and came to the conclusion that the ratio between the magni- tudes of such changes was not constant, but depended to some extent upon the abruptness of the disturbance. The the late Balfour Stewart. 259 Rev. S. J. Perry, Director of the Stonyhurst Observatory, has since paid considerable attention to this point, and in joint communication with Balfour Stewart, some preliminary results are given {Pi'oc. Roy. Soc. XXXIX., p. 363, 1885). The conclusions of the investigation are ^w^w in these words : — (i) In the very great majority of cases the angular value the declination disturbance is greater for Stonyhurst than for Kew. S (2) The ratio -p is certainly greater for disturbances of short than for those of long duration. Our observations are not, however, sufficiently extensive to enable us to represent this ratio graphicall}' as a function of the duration. (3) As far as we can tell from a limited number of observations the value of the above ratio does not depend on the magnitude of the disturbance. I now turn to that part of Stewart's work in which he was principally interested at the time of his death, namel}% the phenomena of sunspots and their connexion with plane- tary configurations and terrestrial meteorolog}-. In a paper published jointly with Dr. Warren de la Rue and Mr. Benjamin Loewy, the size of a sun spot or group of spots is investigated in its passage across the solar disk, in order to determine whether the size varied as some meri- dian opposite one of the planets is traversed. Definite results were obtained for the planets Mercury and Venus ; the average size of a spot in both cases being smallest on that side of the sun which is directly under the planet, and largest 180" away from that point. As regards Venus the result appears both from the observation of Carrington and those taken at Kew. The question of a possible connexion between the temperature range at Kew and the phases of the moon is 26o Dr. Schuster on discussed at length in a paper (Proc. Roy. Soc.^ XXV., p. 102, 1877), and the result seems decidedly in favour of such a connexion, especially in the winter months. During the period 1855-65, as well as during the succeeding ten years, the temperature range, which is the difference between the highest and lowest value of temperature during any given day, shows a minimum at full moon, and a maximum shortly after new moon. It is strange, however, that the researches of Baxendell {Proc. Man. Lit. and Phil. Soc, Session 1879), from observations taken at Southport, have led to a directly opposite result. Baxendell does not give his calculations as interfering in any way with Stewart's result, but rather as tending to show that the influence may be different at different places. It is easy to see, in fact, that if the lunar influence affects, in the first place, the distribution of pressure ■over the globe, so that the path of atmospheric depressions is altered, an increase of temperature range at one place might be coincident with a decrease at another. Neverthe- less, the marked difference in behaviour between two places not further apart than Kew and Southport, show the desirability of further researches ; and now that a connexion between the frequency of thunderstorms and the phases of the moon has been shown to exist by Koeppen and others, the subject no doubt will receive renewed attention. The daily range of magnetic declination is a quantity similar to that of the daily range of temperature, and Stewart has frequently taken it as the basis for his reduc- tions. The daily range exhibits also a lunar period having a maximum both at full and new ir[oon(Proc.Roy. Soc. XXVI, 1877). A similar result had been previously obtained by Mr. Capello, the Director of the Lisbon Observatory. The same paper contains another investigation. The sun spot variation which apparently depends on planetary configuration suggested a search for a similar variation of declination range. It appeared from the result tJic late Balfour Stewart. 261 that during conjunction of Mercury and Venus both sun spots and declination range showed an increased range, but the smallest range coincided with a difference of 90^ between the positions of the two planets. The relative position of Mercury and Jupiter gave a maximum of declination range shortly after conjunction, and a minimum shortly after opposition. As regards the position of Mercury, a maximum and minimum declination range nearly coincided with peri- helion and aphelion. In two further papers (Proc. Roy. Soc, XXVII., p. 81 and 389, 1878) the same results are deduced from the declination ranges of Trevandrum and Prague. Balfour Stewart has, in connexion with others, spent much labour on the discovery of certain short-period inequalities in terrestial and solar phenomena. Fourrier has taught us how a series of observations, however irregular^ may, by a purely analytical process, be represented by a series of harmonic oscillations ; there are an infinite number of ways in which this can be done by varying the length of time within which we wish to represent the series. But the amplitudes and phases of the oscillations thus de- duced have no prophetic virtue, that is to say, from the observations taken within certain limits we can tell nothing as to what will happen outside those limits. If on the other hand we have reason to believe that our series of observa- tions is actually formed by the superposition of certain definite oscillations, which are due to real but unknown causes, we may have to deduce the periodicities of these causes, and this is a different and much more difficult pro- cess. Balfour Stewart has described a method {Proc. Roy. Soc, Vol. XXIX., p. I, 1879) by means of which this can be done, and has applied the method of a number of problems. It is an inherent difficulty of this, as of any other method, that results deduced from a single series do not give us any certain results. Accidental regularities, such as we must expect, can only be eliminated by a repetition of the work, 262 Dr. Schuster on on different sets of observations. Wherever a repetition was possible, Stewart did not spare any pains to repeat his laborious calculations, but no one was better aware than himself, how much remained to be done in that direction. The following are the results which he deduced from a pre- liminary investigation in which he was assisted by Mr. W. Dodgson. 1. The temperature ranges at Kew, Utrecht, and Toronto exhibit certain common periods (around 24 days). 2. Of the curves embodying those periods, that of Kew is most like the mean, and that of Toronto least so. 3. Similar phases appear to occur at Toronto 8 days before they occur at Kew, and occur at Kew one day before they occur a Utrecht. 4. Correcting for these differences of phase, the individual inequalities at Kew, Utrecht, and Toronto are very like the mean of the three and like each other. 5. Of these, the Kew inequalities are most like the mean, the Toronto least so. 6. The declination ranges at Kew and Prague exhibit certain common periods which we may regard as the same, or very nearly the same, as the meteorological periods above indicated. . 7. Similar magnetic phases appear to occur at Kew about one day before they occur at Prague. 8. Correcting for this difference of phase, the individual inequalities at Kew and Prague are very like the mean of the two, and like each other. 9. There is also a less striking likeness between the various magnetical and the corresponding meteorological inequalities. 10. Provisional sun spot records appear to show certain solar inequalities, very like the magnetic and meteorological inequalities in point of period. The connexion between temperature range and sun spot the late Balfour Steivart. 263 areas is further discussed in a paper written jointly with Mr. W. L. Carpenter {Proc. Roy. Soc, Vol. XXXVII., p. i, 1884). The authors describe the results of their calculation as follows : a. Sun spot inequalities around 24 and 26 days, whether apparent or real, seem to correspond closely in period with terrestrial inequalites as exhibited by the daily temperature range at Toronto and at Kew. /3. While the sun spot and the Kew temperature range inequalities present evidence of a single oscillation, the corresponding Toronto temperature range inequalities pre- sent evidence of a double oscillation. y. Setting the inequalities as we have done, the sun spot maximum occurs about eight or nine days after one of the Toronto maxima, and the Kew maximum about seven days after the same Toronto maximum. ^. The proportional oscillation exhibited by the tem- perature range inequalities is much less than that exhibited by the corresponding solar inequalities. They add : " It must be borne in mind that the truth of a connexion between celestial and terrestrial phenomena can only be decided by cumulative evidence of various kinds. " What we claim to have here done is to have given reasons for supposing that there is a correspondence in time scale, and a definite relation in type and phase between sun spot and temperature range inequalities." Similar results are obtained from a comparison by the same authors between apparent inequalities of short period in sun spot areas and diurnal declination ranges at Toronto and Prague. The sun spot period, with its average duration of about eleven years, shows very great irregularities both in the length and amplitude of the oscillation. Stewart has shown (^Mein. Mane. Lit. and Phil^ that from the year 1780 to 1870 264 Dr. Schuster on the curve of solar activity can be best represented as a super- position of three oscillations, one of ten-and-a-half, one of twelve, and a minor one of about sixteen years. The irre- gularities would thus be produced by the beats of these three fluctuations. It will be interesting to see how far further observation will confirm this result. It was in great part owing to Balfour Stewart's influence that a Committee of the British Association was formed at the Canada meeting, " to consider the best means of com- paring and reducing magnetic observations." He was appointed secretary to the committee which has already presented three valuable reports. They contain among other matters a research jointly with Mr. Lant Carpenter on the connexion between magnetic disturbances and the strength of the wind. A good case is made out from the conclusion that high and low disturbance values of magnetic force correspond with, and slightly precede, high and low wind values. Balfour Stewart was the author of several text-books.. His "Primer of Physics," as well as his "Elements of Physics," are well established as sound and clear elementary works. His book on heat is an excellent treatise, and his " Lessons in Elementary Practical Physics," written jointly with Mr. W. W. Haldane Gee, is the most complete compo- sition of experimental methods in physics which has been written. An admirable treatise on the " Conservation of luiergy," forms one of the volumes of the International Science Series. Students of Terrestrial Magnetism will for a long time to come value the clear and, at the same time full account he has given of the present state of the subject in the last edition of the " Encyclopitdia Britannica." His book "The Unseen Universe, or Physical Speculations on a Future State," by Stewart and Tait, was published anonymously at first. It went rapidly through several editions, and in the fourth the authors' names were given. tJie late Balfour Stewart. 265 The following abstract from the preface to the first shows the aim of the book. "Forgetful of the splendid example shown by intellectual giants like Newton and Faraday, and aghast at the materialistic statements now-a-days freely made (often professedly in the name of science), the orthodox in religion are in somewhat evil case. "As a natural consequence of their too hastily reached conclu- sion that modern science is incompatible with Christian doctrine, not a few of them have raised an outcry against science itself This result is doubly to be deplored, for there cannot be a doubt that it is calculated to do mischief not merely to science but to religion. "Our object, in the present work, is to endeavour to show that the presumed incompatibility of science and religion does not exist. This, indeed, ought to be self-evident to all who believe that the Creator of the universe is Himself the Author of Revelation. But it is strangely impressive to note how very little often suffices to alarm even the firmest of human faith." Balfour Stewart was an active member — at one time the President — of the Psychical Society ; believing that every subject must gain by an impartial and philosophical inquiry, and that no subject is beneath the attention of scientific men. He received the Rumford medal of the Royal Society in 1868. At the time of his death he was President of the Physical Society of London, and of the Manchester Literary and Philosophical Society. The following list of papers published by Balfour Stewart does not pretend to be quite complete, but it is believed that none of his more important contributions have been omitted. List of Papers by Prof. Balfour Stewart. 1. On certain laws observed in the mutual action of sulphuric acid and water. Brit. Ass. Rep.^ 1855. Edinb. Roy. Soc. Proc. III., 1857. 2. On the adaptation of the eye to the nature of the rays which emanate from bodies. Victoria Trans. Phil. Soc. I., 1855. S 266 Dr. Schuster on 3. On the influence of gravity on the physical condition of the Moon's surface. Victoria Tra?ts. Phil. Soc. I., 1885. 4. Description of an instrument for registering changes of tempera- ture. Roy. Soc. Proc. VIII., 1856-57. 5. On a proposition in the theory of numbers. Edi?ib. Roy. Soc. Trafis. XXL, 1857. 6. An account of some experiments on radiant heat, involving an extension of Prevost's Theory of Exchanges. Brit. Ass. Rep., 1858. Edijib. Roy. Soc. Trans. XXII., 1861. 7. On some results of the Magnetic survey of Scotland in the years 1857 and 1858, undertaken by the late John Welsh. Brit. Ass. Rep., 1859. 8. An account of the construction of the self-recording magneto- graphs at present in operation at the Kew Observatory. Brit. Ass. Rep., 1859. 9. On radiant heat. Brit. Ass. Rep., 1859. 10. On the light radiated by heated bodies. Roy. Soc. Proc. X., 1859-60. 11. Description of an instrument combining in one a maximum and minimum. Mercurial Thermometer, invented by Mr. James Hicks. Roy. Soc. Proc. X., i860. 12. On the nature of the light emitted by heated tourmaline. Roy. Soc. Proc. X., 1859-60. 13. Note regarding Mr. Ponton's Paper " On certain Laws of Chromatic Dispersion." Phil. Mag. XX., i860. 14. On the radiative powers of bodies with regard to the dark or heat-producing rays of the spectrum. Phil. Mag. XX. i860. 15. On internal radiation in uniaxial crystals. Roy. Soc. Proc. XL, 1860-62. 16. On the great magnetic disturbance of 28th August to Septem- ber, 1859, as regarded by photography at the Kew observatory. Roy. Soc. Proc. XL, 1860-62. 17. On the theory of exchanges and its recent extension. Brit. Ass. Rep., 1861. 18. Researches on radiant heat. Edinb. Roy. Soc. Trans. XXIL, 1861. the late Balfour Stewart. 267 19. Note on the occurrence of flint implements in the drift. Phil. Mag. XXIIL, 1862. 20. On the nature of those red protuberances which are seen on the sun's Hmh during a total eclipse. Phil. Mag. XXIV., 1862. 21. On the nature of the forces concerned in producing the greater magnetic disturbances. Phil. Trans.., 1862. 22. On the connexion between temperature and electrical resis- tance in the simple metals. Edinb. Roy. Sac. Proc. IV., 1862. 23. On the magnetic disturbance which took place on the 14th December, 1862. Roy. Sac. Proc. XII., 1862-3. 24. An account of experiments on the elastic force of a constant volume of atmospheric air, between 32^ F. and 212° F.. and also on the temperature of the melting point of mercury. Phil. Trans.., 1863. 25. On the forces concerned in producing magnetic disturbances. Roy. hist. Proc. IV., 1868. 26. On the sudden squalls of 30th October and 21st November, 1863. Roy. Soc. Proc. XIII., 1863. 27. On the radiation and absorption of gases. Phil. Mag. XXVI. 1863. Annates de Chimie. I., 1864. 28. On the large sun spot period of about 56 years. Astron. Month., Not. XXIV., 1864. 29. On the earth-currents during magnetic calms, and their con- nexion with magnetic changes. Edinb. Roy. Soc. Trans. XXIIL, 1864. 30. On sun spots and their connexion with planetary configura- tions. Edinb. Roy. Soc. Trans. XXIIL, 1864. Edinb. Roy. Soc. Proc. V., 1866. 31. On the origin of the light of the sun and stars. Intellectual Observer V., 1864. 32. On the magnetic disturbance which took place on December 14, 1862. Phil Mag XXVIL, 1864. 33. On the change in the elastic force of a constant volume of dry atmospheric air, between 32° F. and 212° F., and on the temperature of the freezing point of mercury. Phil. Mag. XXVIL, 1864. 26S Dr. Schuster ofz 34. On radiant light and heat. Quarterly Jour 11. Sci. L, 1864. 35. On the sudden Squalls of 30th October and 21st November, 1863. Roy, Soc. Proc. XIII., 1864. 2fi. Remarks on sun spots. Roy. Soc. Proc. XIIL, 1864. Phil. Mag. XXVIIL, 1864. 37. On the velocity of propagation, between Oxford and Kew, of atmospheric disturbances. Brit Meteor. Soc. Proc. 11. , 1865. 38. On Mr. Cook's observation of the solar spectrum. Phil. Mag. XXXI., 1866. 39. On the latest discoveries concerning the sun's surface. Roy. Inst. Proc. IV., 1886. 40. On the existence of a material medium pervading space. Roy. Soc. Proc. IV., 1866. 41. Researches on solar physics. First series. On the nature of sun spots. Ainer. Joiirn. of Sci. XLIII., 1867. 42. Researches on solar physics. Second series. Area-measure- ment of the sun spots observed by Carrington during the seven years from 1 854-1 860 inclusive, a deduction there- from. Amer. Journ. of Sci. XLIIL, 1867. 43. On the errors of aneroids at various pressures. Brit. Ass. Rep. XXXVII., 1867. 44. Note on the secular change of magnetic dip as recorded at the Kew Observatory. Roy. Soc. Proc. XY., 1867. Pliil. Mag., XXXI. 45. On the specific gravity of mercury. Roy. Soc. Proc. XV., 1867. PM.Mag.XXXl. 46. A comparison between some of the simultaneous results of the barographs at Oxford and at Kew. Roy. Soc. Proc. XV., 1867. 47. Description of an apparatus for the verification of sextants designed and constructed by T. Cooke, and recently erected at the Kew Observatory. Roy. Soc. Proc. XVI., 1868. 48. An account of certain experiments on aneroid barometers, made at Kew Observatory, at the expense of the Meteoro- logical Committee. Roy. Soc. Proc. XVI., 1868. Smith- sonian Rep., 1868. Phil. Mag XXXVIL, 1869. the late Balfoiw Steiuart. 269 49. Remarks on meteorological reductions, with especial reference to the element of vapour. Brit. Ass. Rep. XXXIX, 1869. 50. On the sun as a variable star. Roy. Inst. Proc. V., 1869. 51. A preliminary investigation into the laws regulating the peaks and hollows exhibited in the Kew magnetic curves for the first two years of their production. Roy. Soc. Proc, XVIL, 1869. 52. On auroral appearances and their connection with the phe- nomena of terrestrial magnetism. Astron. Soc. Month. Not.^ 1870. Phil. Mag. XXXIX., 1870. 53. Results of the monthly observations of dip and horizontal force made at the Kew Observatory, from April, 1863, to March, 1869, inclusive. Roy. Soc. Proc.., 1870. 54. On the temperature-equilibrium of an enclosure in which there is a body in visible motion. Brit. Ass. Rep. XLI., 187 1. Manchester Lit. c:^ Phil. Soc. Proc. X., 187 1. 55. Recents progres de la physique cosmique. Revue Cours Scie?tt, I., 1871. 56. An account of some experiments on the melting point of paraffin. Manchester Lit. & Phil. Soc. Proc. XIL, 1873. 57. On ethereal friction. Brit. Ass. Rep. XLIII., 1873. 58. On an instrument for measuring the direct heat of the sun. Manchester Lit. ^ Phil. Soc. Me??t. VI., 1875. 59. On the variations of the daily range of atmospheric temperature as recorded at the Kew Observatory. Roy. Soc. Proc. XXV., 1876. 60. On the variations of the daily range of atmospheric tempera- ture as recorded at the Kew Observatory. Roy. Soc. Proc. XXV., 1877. 61. On the variations of the daily range of the magnetic declina- tion as recorded at the Kew Observatory. Roy. Soc. Proc. XXVL, 1877. 62. On the diurnal range of the magnetic declination as recorded at the Trevandrum Observatory. Roy. Soc. Proc. XXVIL, 1878. 63. On the variations of the diurnal range of the magnetic declination as recorded at the Prague Observatory. Roy. Soc. Proc. XXVIL, 1878. 270 Dr. Schuster on 64. Preliminary report to the solar physics Committee on the comparison for two years between the diurnal ranges of magnetic declination as recorded at the Kew Observatory, or the diurnal ranges of atmospheric temperature as re- corded at the observatories of Stonyhurst, Kew, and Falmouth. Roy. Soc, Proc. XXXIV., 1882. 65. On the connexion between the state of the sun's surface and the horizontal intensity of the earth's magnetism. Roy. Phil. Proc. Soc. XXXIV., 1882. 66. On the long-period inequality in rain-fall. Manchester Lit. 6^ Phil. Soc. Mem. VII., 1880. 67. On the cause of the solar diurnal variations of terrestrial magnetism. Phil. Mag., 1886. Stewart and Brito-Capello. Results of a comparison of certain traces produced simultaneously by the self-recording magnetographs at Kew and at Lisbon, especially of those which record the magnetic disturbance of 15th July, 1863. Roy. Soc. Proc. XIII. , 1864. Description of the magnetic storm of the beginning of August, 1865, as recorded by the self-recording magnetographs at the Kew and Lisbon Observatories. Brit. Ass. Rep. XXXV., 1865. Stewart and IV. L. Carpenter. Report to the Solar Physics Committee on a comparison between apparent inequalities of short period in sun spot areas and in diurnal temperature ranges at Toronto and Kew. Roy, Soc. Proc. XXXVIL, 1884. Note on a preliminary comparison between the dates of cyclonic storms in Great Britain and those of magnetic disturbances at the Kew Observatory. Roy. Soc. Proc. XXXVIIL, 1885. On a comparison between apparent inequalities of short period in sun spot areas and in diurnal declination ranges at Toronto and at Prague. Roy. Soc. Proc. XL., 1886. the late Balfour Stezuart. 271 ■Stewart and De la Rue. Further investigations on planetary influences upon solar activity. J^oy. Soc. Froc, 1872. On a tendency observed in sun spots to change alternately from one solar hemisphere to the other. Roy. Soc. Proc. XXI., 1873- Stewart and IViil. Dodgso7i. Preliminary report to the committee on solar physics on the evi- dence in 'favour of the existence of certain short periods common to solar and terrestrial phenomena. Roy. Soc. Proc. XXIX., 1879. Preliminary report to the committee on solar physics on a method of detecting the unknown inequalities of a series of obser- vations. Roy. Soc. Proc. XXIX., 1879. Note on the inequalities of the diurnal range of the declination magnet as recorded at the Kew Observatory. Roy. Soc. Proc. XXIIL, 1879. An analysis of the recorded diurnal ranges of magnetic declina- tion, with the view of ascertaining if these are composed of inequalities which exhibit a true periodicity. Manchester Lit. and Phil. Soc. A/em. VIII., 1881. Stewart and Morisaboo Hiraska. A comparison of the variations of the diurnal range of magnetic declination as recorded at the Observatories of Kew and Trevandrum. Roy. Soc. Proc. XXVIII., 1879. Stewart and Loewy. An account of the base observations made at the Kew Observatory, with the pendulums, to be used in the Indian Trigono- metrical Survey. Roy. Soc. Proc. XIV., 1865. An account of experiments made at the Kew Observatory for determining the true vacuum_and temperature— corrections to pendulum observations. Roy. Soc. Proc. XVII. , 1869. On the tendency observed in sun spots to change alternately from one solar hemisphere to the other. Roy. Soc. Proc. XXL, 1873- 2J2 Balfour Steiuart. Stetvart a?id Ferry. Preliminary results of a comparision of certain simultaneous, fluctuations of the declination at Kew and at Stonyhurst during the years 1883 and 1884, as recorded by the Magnetographs at these Observatories. Roy. Soc. Proc. XXXIX., 1885. Stewart and Boscoe. On the heat of sunshine at London during the twenty-four years 1855 to 1874 as registered by Campbello method. Roy. Soc. Proc. XXIII., 1875. Steiuart and Sidgreaves. Results of a preliminary comparison of certain curves of the Kew and Stonyhurst declination magnetographs. Roy. Soc. Proc. XVII., 1869. Stewart a7id Tait. Preliminary note on the radiation from a revolving disk. Roy. Soc. Proc. XIV., 1865. Phil. Mag. XXIX., 1865. On the heating of a disk by rapid rotation 171 vacuo. Roy. Soc. Proc. XIV., 1865, and XV. and XXXI. Phil Mag XXX., XXXIIL, XXXVII. Annal Phys. Che?n. CXXXVL, 1869. On the heating of a disk by rapid rotation in vacuo. Roy. Soc. Proc. XXI., 1878. Stetvart and others. Three reports of the committee appointed for the purpose of con- sidering the best means of comparing or reducing magnetic observations. Brit. Ass. Reports^ 1885, 1886, 1887. TJie Council. 273 THE COUNCIL OF THE MANCHESTER LITERARY AND PHILOSOPHICAL SOCIETY. April 17, 1888. OSBORNE REYNOLDS, M.A., LL.D., F.R.S. ^XZZ-'^XZ%X^Z\\\%. WILLIAM CRAWFORD WILLIAMSON, LL.D., F.R.S. , Foreign Member of the Royal Swedish Acad. Sc. Sir HENRY ENFIELD ROSCOE, B.A., LL.D., D.C.L., F.R.S. F.C.S., M.P. JAMES PRESCOTT JOULE, D.C.L., LL.D., F.R.S., F.C.S., Corr. Mem. Inst. Fr. (Acad. Sc.) Paris, and Roy. Acad. Sc. Turin. ARTHUR SCHUSTER, Ph.D., F.R.S., F.R.A.S. FREDERICK JAMES FARADAY, F.L.S., F.S.S. REGINALD F. GWYTHER, M.A. CHARLES BAILEY, F.L.S. librarian. FRANCIS NICHOLSON, F.Z.S. ©titer Jttcmbers qI \\\z Cauncil. JAS. BOTTOMLEY, B.A., D.Sc, F.C.S. JOHN BOYD. HAROLD B. DIXON, M.A., F.R.S. WILLIAM HENRY JOHNSON, B.Sc. JAMES COSMO MELYILL, M.A., F.L.S. S. B. WORTHINGTON, C.E. 274 Honorary Members. HONORARY MEMBERS. DATE OF ELECTION. 1847, April 20. Adams, John Couch, LL.D., F.R.S., V.P.R.A.S., F. C. P. S. , Director of the Observatory, and Lowndsean Prof, of Astron. and Geom. in the Univ. of Cambridge. Cor. Mem. Inst. Fr. (Acad. wSci.), &c. The Observatory, Carnbridi^e. 1S43, April 18. Airy, Sir George Biddell, K.C.B., M.A., D.C.L., LL.D., Hon. Mem. R.S.E., R.I.A., f\C.P.S., For. Mem. Inst. Fr. (Acad. Sci.), &c. Ihe White House, Crootiis Hill, Greenwich Park, S.E. 1887, April 19. Armstrong, vSir Wm. George, C.B., D.C.L., LL.D. Ne'.v- castle-on- Tyne. 1886, Feb. 9. Baker, Benjamin. 2, Qiceen^s Square Place, Westminster, S. W. Baker, John Gilbert, F.R.S. K'e7v. Berthelot, Prof. Marcellin, For. Mem. R. S. Paris. Buchan, Alexander, F.R.S.E. *] 2, Northumberland Street, Edinburgh. Bunsen, Robert Wilhelm, Ph.D., For. Mem. R.S., Prof. of Chemistry at the Univ. of Heidelberg. Heidelberg. Buys Ballot, Dr. H. D., Supt. of the Royal Meteor. Institution. Utrecht. Cannizzaro, S. Professor of Chemistry. University of Pome. Cayley, Arthur, M.A., LL.D., D.C.L., V.P.R.A.S., FC.P.S., Sadlerian Prof, of Pure INIaths. in the Univ. of Cambridge, Cor. Mem. Inst. Fr. (Acad. Sci.), &c. Garden House, Cambridge. 1886, Feb. 9. Clausius, Professor Rudolph, For. Mem. R.S. University of Bonn. 1866, Oct. 30. Clifton, Robert Bellamy, M.A., F.R.S., F.R.A.S, Professor of Natural Philosophy, Oxford. Neiv Museiun, Oxford. 1887, April 19. Cornu, Professor Alfred. Ecole Polytechjiique, Paris. 1886, Feb. 9. Dawson, Sir John William, C.M.G., M.A., F.R.S., LL.D., F. G . S . Mc Gill College, Montreal. 1888, April 17. Dewalque, Gustave, Professor of Geology. University of Liege. i860. Mar. 9. Frankland, Edward, Ph.D., M.D., LL.D., D.C.L., V.P.C.S, F.R.S., Cor. Mem. Inst. Fr. (Acad. Sci.), &c. The Yews, Reigate Hill, Reigatc. 1843, ^^eu. P>isiani, nobile Paola, Pros., late Astron. at tlic Observ. of Brera, Milan, Mem. Imper. Roy. Instit. of Lombardy, Milan, and Ital. Soc. Sc. Milan. 1886, 1886, 1886, Feb. Feb. Feb. 9- 9- 9- i860. April 17- 1887, April 19. 1888, April 1859, Jan. 17. 25- Honorary Members. 275 DATE OF ELECTION. 1848, Jan. 25. Hind, John Russell, LL.D., F.R.S., F.R.A.S., Superinten- dent of the Nautical Almanac. Cor. Mem. Inst. Fr. (Acad. Sci.). 3, Cambridge Park Gardens^ Tiuickenham. 1888, Feb. 9. Hirn, Gustav Adolph. Col mar. 1881, April 17. Hittorf, Johann Wilhelm, Professor of Physics. Polytech- nicum, MiXnsier. 1886, Feb. 9. Helmholtz, Geheimrath Hermann von, LL.D., For. Mem. R.S. President der Physikalisch-technischen Reichsanstalt. Berlin. 1866, Jan. 23. Hofmann, A. W., Ph.D., M.D., LL.D., F.R.S., Cor. Mem. Inst. Fr. (Acad. Sci.), &c. 10, Dorotheenstrasse, Bei'lin. 1869, Jan. 12. Huggins, William, LL.D., D.C.L., F.R.S., F.R.A.S., Cor. Mem. Inst. Fr. (Acad. Sci.). 90, Upper Tube Hill, Brixton, London, S. W. 1872, April 30. Huxley, Thomas Henry, M.D., Ph.D., LL.D., D.C.L., P.P.R.S., Hon. Prof, of Biology in Royal School of Mines. Cor. Mem. Inst. Fr. (Acad. Sci.), &c. 4, Marl- borough Place, Abbey Road, N. IV. 1852, Oct. 16. Kirkman, Rev. Thomas Penyngton, M.A., F.R.S,, Croft Rectory, near Warrington. 1886, Feb, 9. Kopp, Prof. Flermann. Heidelberg. 1887, April 19. Langley, Prof. S. P., Alleghany Observatory, Pittsburg, U.S. 1887, April 19. Laveleye, Emile de, Liege University. 1887, April 19. Lockyer, Norman, F.R.S., Cor. Mem. Inst. Fr. (Acad. Sci. ). Science School, K'ensington. 1887, April 19. Newcomb, Prof. Simon, For. Mem. R.S. Johns Hopkins University, Baltimore, U.S. 1844, April 30. Owen, Sir Richard, K.C.B., M.D., LL.D., F.R.S., F.L.S., F.G.S., V.P.Z.S., F.R.C.S. Ireland, Hon. M.R.S.E., For. Assoc. Inst. Fr. (Acad. Sci.), 6cc. Sheen Lodge, Richmond. 1886, Feb. 9. Pasteur, Louis, For. Mem. R.S. Paris. 1 85 1, April 29. Playfair, Rt. Hon. Lyon, K.C.B., LL.D., Ph.D., F.R.S., F.G.S., M.P., V.P.C.S., &c. 68, Onsloiv Gardens, London, S. W. 1866, Jan. 23. Prestwich, Joseph, F.R.S., F.G.S., Cor. Mem. Inst. Fr. (Acad. Sci.). Shoreham, near Sevenoaks. 1866, Jan. 23. Ramsay, Sir Andrew Crombie, LL.D. F.R.S., F.G.S., 15, Cromivell Crescent, South Kensington, London. 1849, J^n. 23. Rawson, Robert, F.R.A.S. Havant, Hants. 276 Honorary Members. DATE OF ELECTION. 18S6, Feb. 9. Rayleigh, John William Strutt, Lord, M.A., D.C.L., (Oxon.), LL.D. (Univ, McGill), Sec. R.S., F.R.A.S. Terling Place, Witham, Essex. 1887, April 19. Romer, Dr. Fred. Bj-eslau. 1872, April 30. Sachs, Julius, Ph.D. Wurzlnirg. 1869, Dec. 14. Sorby, Henry Clifton, LL.D., F.R.S,,F.G.S.,&c. Broom- field, Sheffield. 1 85 1, April 29. Stokes, George Gabriel, M.A., M.P., LL.D., D.C.L., Pres. R.S., Lucasian Professor of Mathem. Univ. Cambridge, F.C.P.S., Cor. Mem. Inst. Fr. (Acad. Sci.), &c. Lens- field Cottage, Cambridge. 1886, Feb. 9. Strasburger, Professor. Bonn. 1861, Jan. 22. Sylvester, James Joseph, M.A., D.C.L., LL.D., F.R.S., Savilian Prof, of Geom. in the Univ. of Oxford, Cor. Mem. Inst. Fr. (Acad. Sci.), &c. Neiu College, Oxford. 1868, April 28. Tait, Peter Guthrie, M.A., F.R.S.E., &c.. Professor of Natural Philosophy, Edinburgh. 38, Geo7'ge Square, EdinhtirgJi. 1851, April 22. Thomson, Sir William, M.A., D.C.L., LL.D., F.R.S.S. L. and E. Prof, of Nat. Phil, in Univ. of Glasgow. Yox. Assoc. Inst. Fr. (Acad. Sci.), &c. 2, College Glasgozi>. 1872, April 30. Trecul, A,, Member of the Institute of France. Paris. 1886, Feb. 9. Tylor, Edward Burnett, F.R.S., D.C.L. (Oxon.), LL.D. (St. And. and McGill Colls.) 1868, April 28. Tyndall, John, LL.D., M.D., D.C.L., Ph.D., F.R.S.,. F.C.S. Poyal Institution, London, W. 1886, Feb. 9. Young, Prof. C. A. Princeton College, A\ /., U.S. 18S8, April 17. Zirkel, Ferdinand, Professor of Mineralogy. University of Leipsic. Corresponding Members. 277 CORRESPONDING MEMBERS. DATE OF ELECTION. i860, April 17. Ains worth, Thomas. Ckator Mills, near Egremont, Whitehaven. 1 86 1, Jan. 22. Buckland, George, Professor, University College, Toronto. Toronto. 1870, Mar. 8. Cockle, The Hon. Sir James, M.A., F.R.S., F.R.A.S., F.C.P.S., Pres. Math. Soc. 12, St. Stephen's Road, Bayswater, London. 1866, Jan. 23. De Caligny, Anatole, Marquis, Corresp. Mem. Acadd. Sc. Turin and Caen, Socc. Agr. Lyons, Sci. Cherbourg, Liege, &c. 1861, April 2. Durand-Fardel, Max, M.D., Chev. of the Legion of Honour, &c, 36, Rne de Lille, Paris. 1849, April 17. Girardin, J., Off. Legion of Honour, Corr. Mem. Instit. France, &c. Lille. 1S50, April30. Harley, Rev. Robert, F.R.S., F.R.A.S. 17, Wellington Square, Oxford. 1882, Nov. 14. Herford, Rev. Brooke. Arlington Street, Boston, U.S. 1862, Jan. 7. Lancia di Brolo, Frederico, Due, Inspector of Studies, (Sec. Palermo. 1S595 J^^^' 25. Le Jolis, Auguste-Fran^ois, Ph.D., Archiviste perpetuel and late President of the Soc. Nat. Sc. Cherbourg, &c. Cherbourg. 1857, Jan. 27. Lowe, Edward Joseph; F.R.S., F.R.A.S., F.G.S., Mem. Brit. INIet. Soc, &c. Shij'enetvton Hall, near Chepstow, 1862, Jan. 7. Nasmyth, James, C.E., F.R.A.S., &c. Penshurst, Tun- bridge. 1867, Feb. 5. Schonfeld, Edward, Ph.D., Director of the Mannheim Observatory, 278 Ordinary Members. ORDINARY MEMBERS. DATE OF ELECTION'. l88i,Jan. 11. Adamson, Daniel, M. Inst. CK., F.G.S. The Towers,. Didsbiiry. 1861, Jan. 22. Alcock, Thomas, M.D., Extr. L.R.C.P. Lond., M.R.C.S. Engl., L.S.A. Oakfield, Ashton-on- Mersey. 1873, T^n. 7. Allmann, Julius. 70, Deansgate. 1870, Dec. 13. Angell, John, F.C.S., F.I.C. 81, Ditcie Grove, Oxford Road. 1861, Jan. 22. Anson, Ven. Archd. George Henry Greville, M.A. Birch Rectory, Rttsholine. 1S85, Nov. 17. Armstrong, Thomas, F.R.M.S. Brookfield, Urmstou : Deansgate. 1S37, Aug. II. Ashton, Thomas. 36, Charlotte Street. 1 88 1, Nov. I. Ashton, Thomas Gair, M.P., M.A. 36, Charlotte Street. 1887, Nov. 16. Ash worth, J. Jackson. 35, Mosley Street, City. 1865, Nov. 15. Bailey, Charles, F.L.vS. Ashfield, College Road, IVhalley Range, JManchester. 1888, Feb. 7. Bailey, Alderman W. H. Summerjield, Eccles Ne7t> Road 1883, Oct. 16. Baker, Harry, F.G.S, 262, Ply;nonth Grove. 1876, Nov. 28. Barratt, Walter Edward. A'ersal, Higher Broiightoii. 1867, Nov, 12. Barrow, John. Beechfield, Folly Lane, Swinton. 1878, Nov. 26. Bedson, Peter Phillips, D.Sc. Durham College of Science, Newcastle-on- Tyne. 1868, Dec. 15. Bickham, Spencer H. Oakwood, Alderley Edge. 1861, Jan. 22. Bottomley, James, D.Sc, B.A., F.G.S. 220, Lower BrotigJiton Road. 1875, Nov. 16. Boyd, John. Sandiway House, Palatine Road, Didsbitry. 1855, April 17. Brockbanlc, William, F.G.S., F.L.S. Prince's Cha/nbers, 26, Pall Mall. 1 86 1, April 2. Brogden, Henry, F.G.S. Hale Lodge, Altriiichani. 1844, Jan. 22. Brooks, Sir William Cunliffe, Bart., M. A., M. P. Bank, 92, ICing Street. i860, Jan. 23. Brothers, Alfred, F.R.A.S. 12, Sivinton Avenue, Man- chester. 1886, April 6. Brown, Alfred, M.A. , M.B. Clare/uont, Higher Brozighton. 1846, Jan. 27. Browne, Henry, M.A. (Glas.), M.R.C.S. (Lond.), M.D. (Lond.). Heaton Afersey. 1872, Nov. 12. Burghardt, Charles Anthony, Ph.D. 35, Fountain Street. [854, April 18. Christie, Richard Copley, M.A., Chancellor of the Diocese, Glenwood, Virginia Water, Staines. . 1841, April 30. Clay, Charles, M.D., Extr. L.R.C.P. Lond., M.R.C.S,, Edin. 39, Queen Street, (North), BlackfooL Ordinary Members. 279 DATE OF ELECTION. 1886, Dec. 14. Cohen, J. B., Ph.D. The O^vens College. 1884, Nov. 4. Corbett, Joseph. 9, Albert Sqtcare. 1853, Jan. 25. Cottam, Samuel, F.R.A.S., F.R. Hist. S., F.C.A. 49, Spring Gai'dens. 1859, Jan. 25. Coward, Edward. Heatoii Mersey, near Manchester. 1861, Nov. 12. Coward, Thomas. Higher Do7vns, Altrijicham. 1849, Jan. 25. Crowther, Joseph Stretch. Endsleigh, Alder ley Edge. 1876, April 18. CunHffe, Robert Ellis. The Poplars, Eccles Old Roady Eccles. 1854, Feb. 7. Dale, John, F.C.S. i, Chester Terrace, Chester Road. 1 87 1, Nov. 8. Dale, Richard Samuel, B.A. i, Chester Terrace, Chester Road. 1853, April 19. Darbishire, Robert Dukinfield, B.A., F.S.A., F.G.S., 26, George Street. 1878, Nov. 26. Davis, Joseph. Engineer''s Office. Lancashire and York- shii'e Railivay., Hitnt''s Bank. 1S69, Nov. 2. Dawkins, William Boyd, M.A., F.R.S., F.G.S., F.S.A., Assoc. Inst. C.E., Hon. Fellow Jesus College, Oxford; Professor of Geology in Owens College, Curator of the Manchester INTuseum. The Oioens College. 1861, Dec. 10. Deane, William King. Almondbiiry Place, Chester Road. 1879, Mar. 18. Dent, Hastings Charles, F.L.S., F.R.G.S. 20, Thurloe Square, London, S. IV. 1887, Feb. 8. Dixon, Harold B., M.A., F.R.S., Professor of Chemistry. The Oivens College. 1886, Mar, 9. Dodgshon, John. Kingstone Road, Didslnny. 1883, Oct. 2. Faraday, Frederick James, F.L.S., F.S.S. Ramsay Lodge, Bu7'nage Lane, Levenshiilme. Gee, W. W. Haldane, B.Sc. The Oivens College. Greg, Arthur. Eagley, near Bolton. Grimshaw, Harry, F.C.S. Thornton Vieiv, Clayton. Grimshaw, William. Stoneleigh, Sale. Gwyther, R. F., M.A., Fielden Lecturer in Mathematics, Owens College. The Oivens College. 1887, Feb. 21. Hall, Alfred Daniel, Hnliiie Grainmar School, Alexandra Park. 1878, April 30. Harland, William Dugdale, F.C.S. 25, Acomb Street, Greenheys, and 48, King Street, Manchester. 1862, Nov. 4. Hart, Peter. Messrs. Tennants cf Co., Mill Street, ClaytoJi, N., Manchester. 1873, Dec. 16. Heelis, James. 71, Princess Street, 1828, Oct. 31. Henry, William Charles, M.D., F.R.S. Haffield, near Ledbury, Hei-efordshire. 1833, April 26. Heywood, James, F.R.S,, F.G.S,, F.S.A. 2^, Kensing- ton Palace Gardens, London, W. 1864, Mar. 22. Pleywood, Oliver. Bank, St. Ami's Street. 1886, Feb. 9. 1 88 1, Nov. I. 1874, Nov. 3' 1888, Feb. 7. 1875, Feb. 9. 28o Ordinary Members. DATE OF ELECTION. 1S84. Jan. 8. Ilodgkinson, Alexander, M.B., B.Sc. 18, *S'/. [ohn Street, Manchester. 1846, Jan. 27. Holden, James Piatt. 3, Temple Bank, Smedley Lane, Cheetliam. 1887, April 19. Holmes, Ralph, B. A. Hulme Grammar School, Alexandra Park. 1S82, Oct. 17. Holt, Henry. The Cedars, Didsbtoy. 1884, T^n* S. Hopkinson, Charles. 29, Princess Street. 1873, Dec. 2. Howorth, Henry H., F.S.A., M.P. Bentcli^e House, Eccles. 1884, Jan. 8. Hurst, Charles Herbert. The Oiuens College. 1888, April 17. Hutton, James Arthur. Victoria Park, Rusholme» 1870, Nov. I. Johnson, William H., B.Sc. 26, Lever Street. 1878, Nov. 26. Jones, Francis, F.R.vS.E., F.C.S. Grammar School. 1885, Dec. I. Jones, Henry, B.A. Norman. Road, Rusholme. 1842,' Jan. 25. Joule, James Prescott, D.C.L., LL.D., F.R.S., F.C.S., Hon. Mem. C.P.wS., and Inst. Eng. Scot., Corr. Mem. Inst. Fr. (Acad. Sc) Paris, and Roy. Acad. Sc. Turin. 12, War die Road, Sale. 1886, Jan. 12. Kay, Thomas, J. P. Moorjield, Stockport. 1852, Jan. 27. Kennedy, John Lawson. 47, Mosley Street. 1862, April 29. Knowles, Andrew. Siointon Old Hall, Swinton. 1886, Mar. 9. Lamb, Horace, M.A., F.R.S., Professor of Mathematics at the Owens College. 106, Palatine Road, Didsbury. 1884, Jan. 8. Larmuth, Leopold. 96, Mosley Street. 1863, Dec. 15. Leake, Robert, M.P. The Dales, Whitefield. 1884, April 15. Leech, Daniel John, Professor, M.D. The Oivens College. 1850, April 30. Leese, Joseph. Messrs. S. 6^ E. Leese, Fylde Road Mill, Preston. 1884, Jan. 22. London, Rev. Herbert, M.A. Pocklington, Yorkshire. 1857, Jan. 27. Longridge, Robert Bewick. Yezv-T^-ee House, Tabley, Knutsfoj-d. 1870, April 19. Lowe, Charles, F.C.S. Summerfield House, Reddish, Stockport. 1866, Nov. 13. McDougall, Arthur, B.Sc. Clifton Lodge, Gore Street, Greenheys. 1S59, Jan. 25. Maclure, John William, M. P., F.R.G.S. What ley Range. 1875, Jan. 26. Mann, John Dixon, M.D., M.R.C.P. Lond. 16, St. John Street. 1879, Dec. 2. Marshall, Arthur Milnes, M.A., M.D., D.Sc, F.R.S., Professor of Zoology, Owens College. The Owens College. 1864, Nov. I. Mather, William. Lron Works, Salford. 1873, M^i"' ^^' Melvill, James Cosmo, M.A., F.L.S. I\ersal Cottage, Prestivich. 1879, Dec. 30. Millar, John Bell, M.E., Assistant Lecturer in Engineering, Owens College. The Ozvens College. 1 881, Oct. 18. iMond, Ludwig, F.C.S. Winnington Hall, NortJnuich. Ordinaiy Members. 281 DATE OF ELECTION. 1 86 1, Oct. 29. Morgan, John Edward, M.D., M.A., f\R.C.P. Lond., « F.R. Med. and Chir. S., Professor of Medicine in the Victoria University, i, St. Peter's Square. 1873, Mar. 4. Nicholson, Francis, F.ZS. 62, Fountain Street. 1862, Dec. 30. Ogden, Samuel. 10, Mosley Street West. 1884, April 15. Okell, Samuel, F.R. AS. Grange Road, Bowdon. 1861, Jan. 22. O'Neill, Charles, F.C.S., Corr. Mem. Ind. Soc. Mulhouse 72, Den/nark Bond. 1844, April 30. Ormerod, Henry Mere, F.G.S. 5, Clarence Street. 1861, April 30. Parlane, James. RusJiolme. 1876, Nov. 28. Parry, Thomas, F.S.S. Grafton House, Ashton-under- Lyne. 1 88 1, Nov. 29. Peacock, Richard, M.P., M. Inst. C.E. Gorton Hall, Manchester. 18S5, Nov. 17. Phillips, Henry Harcourt, F.C.S. 18, Exchange Street. 1854, Jan. 24. Pochin, Henry Davis, F.C.S. Bodnajit Hall, Conzvay. 1854, Feb. 7. Ramsbottom, John, M. Inst. C.E. Fernhill, Alderley Edge. 1859, April 19. Ransome, Arthur, M.A., M.D., Cantab., F. R,S., M.R.C.S. I, St. Peter' s Square. 1888, Feb. 21. Ree, Alfred, Ph.D., F.C.S. 121, Manchester Road, Mid- diet on. 1869, Nov. 16. Reynolds, Osborne, LL.D., M.A., F.R.S., M. Inst.C.E., Professor of Engineering, the Owens College. Lady- barn Road, Falloivfield. 1883, April 3. Rhodes, James, M.R.C.S. Glossop. 1880, Mar. 23. Roberts, D. Lloyd, M.D., F.R.S. Ed., F.R.C.P. (London). Ravensrc'ood, Broughton Park. i860, Jan. 24. Roberts, Sir William, M.D., B.A., F.R.S., F.R.C.P., Lond. 89, Mosley Street. 1S64, Dec. 27. Robinson, John, M. Inst. C.E. Atlas Works, Great Bridgewater Street. 1858, Jan. 26. Roscoe, Sir Henry Enfield, B.A., LL.D., D.C.L., F.R.S., F.C.S., M.P. 64, Queen's Gate, London. \o%. High Street, Chorlton-on-Medlock. 185 1, April 29. Sandeman, Archibald, ALA. Garry Cottage, near Perth. 1870, Dec. 13. Schorlemmer, Carl, LL.D., F.R.S., F.C.S. The Chvens College. 1842, Jan. 25. Schunck, Edward, Ph.D., F.R.S , F.C.S. Kersal, Man- chester. 1873, Nov. 18. Schuster, Arthur, Ph.D., F.R.S., F.R.A.S. The Oiuens College. 1 88 1, Nov. 29. Schwabe, Edmund Salis, B. A. d,\, George Street . 1886, Oct. 5. Sidebotham, George William, M.R.C.S. Hyde. 1886, April 6. Simon, Henry, C.E. Darwin House. Didsbury. 1876, Nov. 28. Smith, James. 35, Cleveland Road, Crunipsall. 1859, Jan. 25. Sowler, Thomas 24. Cannon Street. 1884. Jan. 8. Swanwick, Frederick Tertius, M. A. The Owens College. T 282 Ordinary Members. DATE OK ELECTION. 1884, Mar, 18. Thompson, Alderman Joseph. Riveisdale, Wilmslo7v 1873, April 15. Thomson, William, F.R.S.E., F.C.S., F.I.C. Royal In- stitution. i860, April 17. Trapp, Samuel Clemenl. 88, Mosley Street. 1879, Dec. 30. Ward, Thomas. Brookjield House, Nor thwich. 1873, Nov. 18. Waters, Arthur William, F.G.S. Care of Mr. /. West, Microscopical Society, King's College^ London. 1857, Jan. 27. Wel)b, Thomas (^eorge. Glass Works, Kirhy Street, Ancoats. 1859, Jan. 25. Wilde, Henry, F.R.S. T lie Hurst, Ahhrley Edge. 1859, April 19. Wilkinson, Thomas Read. Manchester and Salford Bank, Mosley Street. 1874, Nov. 3. Williams, William Carlelon, B.Sc, Professor of Chemistry. Firth College, Sheffield. 1888, April 17. Williams, E. Leader, M.I.C.E. Bo7. 93> 104 Microscopical and Natural History Section - - - pp. 88, 99 Physical and Mathematical Section - - - - - p. 89 Memoirs :— An application of Huyghens' Principle to a spherical wave of light. By R. F. Gwyther, M.A. - - p. 61 Notes on a Small Collection of Mosses from Mauritius. By J. Cosmo Melvill, M.A., F.L.S. - - p. 100 MANCHESTER: 36, GEORGE STREET. Ipiice, Zwo SbiUings. Fourth Series. Vol. i : No. 4. MEMOIRS AND PROCEEDINGS OF THE MANCHESTER LITERARY & PHILOSOPHICAL SOCIETY. 1887-8. CONTENTS. Proceedings pp. 121, 135 Microscopical and Natural History Section - - - p. 134 Memoirs :— On the change of incidence of Small-Pox at different ages during the years 1848-86. Part I. By R. F. Gwyther, M.A. P- 105 A method of calculating the Electrostatic Capacity of a Conductor. By Henry Holden, B.Sc, Bishop Berkeley Fellow in Physics at the Owens College, Manchester, Communicated by Professor Schuster, F.R.S. p. 112 On the change of incidence of Small- Pox at different ages. Part II. By R. F. Gwyther, M.A. - p. I2i MANCHESTER; 36, GEORGE STREET. Fourth Series. Vol. i : No. 5. MEMOIRS AND PROCEEDINGS OF THE MANCHESTER LITERARY & PHILOSOPHICAL SOCIETY. 1887-8. CONTENTS. Proceedings pp. 143, 159 Report of the Council ------- p. 143 Mathematical and Physical Section - - - pp. 137, 138 Microscopical and Natural History Section - - - p. 139 Memoirs : — Descriptions of twenty-three nev/ species of Hymen- optera. By P. Cameron. Communicated by Chas. Bailey, F.L.S. P« i59 A survey of the genus Cyprasa (Linn.), its Nomenclature, Geographical Distribution, and Distinctive Affinities ; with descriptions of tw^o new species and several varieties. With two Plates. By James Cosmo Melviil, M.A., F.L.S. p. 184 A Catalogue of the species and varieties of Cypraea, arranged on a new circular system, in accordance with true sequence of affinity. By James Cosmo Melviil, M.A., F.L.S. p. 238 Memoir of the late Professor Balfour Stewart, LL.D., F.R.S., By Professor A. Schuster, Ph.D., F.R.S., F.R.A.S. p. 253 List of the Council and Members - - . - p, 273 Title Page and Index to the Volume. MANCHESTER: 36, GEORGE STREET. 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