Dec. iS, 1884] 



NA TURE 



163 



Kcmpc. F.R.S.) made a short communication as to the mode 

 iof of the well-known theorem that. MADMJl C FA be 

 a hexagon in a plane, and if A B C be colltnear and D E F be 

 1 ' illinear, then the intersections of the opposite sides of the 

 hexagon are also collinear. — Mi. G. HeppeJ stated the following 

 property of the equation to a central conic, ax" + zhxy + 

 = o, which he had not met with in the ordinary text- 

 books. The co-ordinates being rectangular, then, in the case of 



the ellipse, if - be + "' , the major axis passes through the first 



[uadrant : in the case of the hyperbola, if - be - "'•' . the transi 1 1 se 

 1 rough that quadrant. This property is proved by 



;ing the equation transformed to - ± '■- =1, and then 

 p- a- 



■ ruling back again, so as to make the equation identical 

 w i tli the original equation. The comparison of coefficients 



lie above law. — The President communicated a result he 



rained in elliptic functions, which will appear in a forfh- 

 :oming 1 



Zoological Society. December 2 — Dr. St. George Mivarti 

 -.. Vice-President, in the chair. — Col. Biddulph exhibited 

 fed specimen of the Will Sheep of Cyprus [Ovis ophion), 

 ,ent for presentation to the I'.ritish Museum by Sir Robert Bid- 

 dulph, the High Commissioner of C yprus. — Col. Biddulph also 

 exhibited three heads of the Wild Sheep of Beluchistan, named 

 Ovis blanfordi by Mr. Hume, and drew attention to their simi- 

 larity to Ovis cycloceros from the Salt Range, which led him to 

 express doubts as to the distinctness of Ovis blanfordi as a 

 species. — The Secretary called the attention of the meeting to 

 on July 5 last, of the Greater Vasa Parrot (Coracopsis 

 . presented u< the Society by the late C. Telfair, Esq., in 

 July 1S30, which had thus passed fifty-four years in the Society's 

 1 hardens, and made some observations on a peculiar habit of this 

 species. — A communication was read from the Rev. A. M. Nor- 

 man and the Rev. T. R. R. Stebbing, containing an account of 

 the first portion of the Crustacea Isopoda dredged during the 

 expeditions of the Porcupine, Lightning, and Valorous. The 

 memoir contained descriptions of the representatives of the three 

 famiii tpseudidae, and Anrhuridae obtained during 



the several expeditions. A great number of new forms, chiefly 

 from deep water, including several genera [Sphyraphus, Also- 

 fattais, and Tanaclla among the Tanaidte, and Anthelura, 

 Hyssura, Cyathura, and Calathura among the Anthuridre), were 

 described. — Mr. G. E. Dobson, F.R.S., exhibited a diagram 

 designed to illustrate the evolution of the Mammalia, after 

 Huxley. — Prof, F. Jeffrey Bell read the fifth of his series of 

 is in Holothuroidea. The present paper gave some further 

 information on the characters of the Cotton-Spinner (Solothuria 

 . — Mr. J. Bland Sutton read a paper on the parasphenoid, 

 mer, and the palato-pterygoid arcade of the vertebrated 

 skeleton Mr. Sutton came to the conclusion that the para- 

 fishes was the homologue of the vomer of mammals. 

 — Mr. ( .. A. Boulenger, F.Z.S., read some notes on the edible 

 1, traduced into England, which he referred to two forms — 

 escuhnta lypica of France and Belgium, and liana escn- 

 Itnta lessona of Italy. — A communication was read from the 

 Count T. Salvadori containing remarks on certain species of 

 birds from Timor Laut. — A communication wa? read from Mr. 

 1 . P. Ramsay, C.M.Z. S., conlaiim tption of a sup- 



posed new species of Flycatcher from New Guinea, proposed 

 to be called khipidura fallax. — Mr. I". Day read the third of 

 his papers on races and hybrids among the Salmonidae. The 

 author gave an account of how the salmon, which had been 

 raised in fresh water at Howietown, had been artificially 

 spawned ; and point' ill the hybrids between the 



salmon and the tor 1 sterile, while the hybrids 



between the trouts and proved fertile. 



Geological Society, November 19.— Prof. T. G. Bonney 

 F.R.S., President, in the chair. — Nicol Brown, James Charles 

 in, Herbert W. Hughes, and Rev. Samuel Pilling 

 were elected Fellow, : Prof. A. L. O. Descloizeaux, of 

 . a Foreign Member, rid Prof. Hermann Credner, of 

 Leipzig, a Foreign Correspondent of the Society. — The following 

 communications were read : — Note on the resemblance of the 

 upper molar teeth of an Eocene mammal {Neoplagiaulax, Le- 

 moine) to those of Tritylodon, by Sir Richard Owen, K.C.B.. 

 F.R.S. In this paper the author referred to the genus Neo- 

 piagianlax, described by M. Lemoine from the Eocene of Rheims, 



:i presenting premolars so like those of the Mesozoic genus 

 Plagiaulax as to have suggested the above name, while the true 

 molars in the upper jaw resembled those of South African 

 genus Tritylodon even more nearly than those of Microlesies and 

 us, with which the latter were compared. The lower 

 molars of Neoplagiaulax have only two, instead of three, longi- 

 tudinal series of tubercles ; and the author suggested that this 

 may have been the case also in Tritylodon ; and that the 

 detached molars, on which the genus Microlesies is founded, 

 may also belong to the lower jaw. — On the discovery in one 

 of the bone-caves of Creswell Crags of a portion of the 

 upper jaw of Elepkas primigenius, containing, in situ, the first 

 and second milk-molars (right side), by A. T. Metcalfe, 

 F.G.S. The specimen exhibited to the Society and now 

 described was obtained from one of the Creswell bone-caves, 

 before the commencement of their systematic exploration by a 

 Committee of the British Association. The bone-caves are in 

 the Lower Magnesian Limestone of the Permian, not far from 

 the southern limit of that deposit near Nottingham. The locality 

 was described, and it was shown that the ravine in which the 

 caves occur has been cut in the limestone by the little river 

 Wollen, which probably began by excavating a cavern the whole 

 length of the ravine. The roof of this cavern must have fallen 

 in, and the minor lateral caverns, in which bone-deposits are 

 found, are now similarly being converted into side ravines. The 

 fos-il was found in "Pin-Hole Cave," the most westerly on the 

 north or Derbyshire side of the ravine, about six inches below 

 the base of the surface-soil, here four inches deep. The cave 

 has been described in the Society's Journal (vol. xxxi. p. 679), 

 by Rev. J, M. Mello, who in 1875 obtained from this spot bones 

 of the Arctic fox (Cam's lagopus). As the particular mammoth 

 teeth (first and second milk-molars of the upper jaw) occurring 

 in the fossil were wanting in the National Collection, the author 

 lias undertaken to present the specimen to the British (Natural 

 History) Museum. — Notes on the remains of Elephas primigenius, 

 from the Creswell bone-cave, by Sir R. Owen, K.C.B., F.R.S. 

 The author noticed the various descriptions by Cuvier and him. 

 self of milk-molars of Elephas primigenius, and pointed out that 

 all hitherto known were found detached. The present is the 

 first known occurrence of the two earliest milk-molars in situ. 

 The specimen discovered by Mr. Metcalfe is a portion of the fore 

 part of the maxilla of a very young elephant with the teeth of the 

 right side preserved, the corresponding teeth of the left side and 

 their sockets having been broken away. Of the two teeth thus 

 obtained descriptions and measurements were given. The first 

 tooth is much worn, but only the anterior portion of the second 

 has undergone wear, the two hindmost divisions of this tooth 

 not having risen into use. It is shown that these first teeth of 

 E. primigenius differ much less from the corresponding milk- 

 molars of the Indian elephant than the later teeth do, the thick- 

 ness of the constituent enamel-plates being but little less in 

 proportion, and the principal distinction being the greater relative 

 breadth of the second molar, especially towards the base of the 

 crown. — On the stratigraphical position of the Lower and Middle 

 Jurassic Trigonia: of North Oxfordshire and adjacent districts, 

 by Edwin A. Walford, F.G.S. The author spoke of the value of 

 the Trigonia as stratigraphical guides, and of the wealth of the 

 Oolitic deposits of North Oxfordshire in number of species as 

 well as of individual forms. He alluded to the recent discovery 

 by Northampton geologists of Trigonia lilcrata and T. pulchella 

 in the centre of their county. By the presence of certain 

 Trigonia as well as of corals and bored stones he endeavoured 

 to prove the extension of a stratum at the base of the Clypeus- 

 grit at Fawler, as far as Hook Norton, also in North Oxfordshire, 

 where the bulk of the Inferior Oolite was of an altogether 

 different type. In Mr. Walford's list were nearly thirty species 

 and varieties from the Bajocian beds. To the lower horizons 

 there belonged but one local form, and no species of special 

 stratigraphical value. The presence of a few other fossils sup- 

 posed to lie characteristic was the only evidence of beds below^ 

 the zone of Ammonites murchisonue. Series C, which appeared 

 to be of the age of the lower Trigonia-grit, had yielded the 

 greater p.art of the Trigonia mentioned, several of them being 

 peculiar to the horizon, whilst others were local species. The 

 higher beds had yielded some apparently undescribed forms, 

 whilst hitherto unrecorded species were quoted from the Great 

 Oolite and Forest Marble. One species (7. lycettii) was 

 described as new. 



Chemical Society, December 4. — Dr. Perkin, F.R.S., 

 President, in the chair. — The following papers were read : — 



