May 25, 1887] 



NATURE 



95 



specimens of which are in the British Museum pal?eontolo;;ical 

 collection. The recently discovered Hypcrodapcdon skeleton 

 was of nearly the same size as that formerly described, and must 

 have belonged to an individual about 6 or 7 feet in length. 

 The specimen was exposed by the splitting of a large block of 

 sandstone, and comprised the skull, the vertebral column as far 

 as the root of the tail, all the bones of the left and of part of the 

 right fore-limb, and those of the right hind-limb, the whole 

 almost in their original relations. Tne bones were described in 

 order and compared with those oi Sphenodon, the most important 

 differences in Hypcrjdapedon being the following : — (i) The 

 centre of the presacral vertebrae are ossified throughout and more 

 or less opisthocoelous, e-pecially in the cervical region. (2) The 

 anterior cervical vertebra have long and strong ribs. (3) The 

 external nares are not separated by bone. (4) Conjoined pre- 

 maxillary bones form a long, conical, curved, pointed rostrum, 

 which is received between the rostral processes of the mandible. 

 All these were devoid of teeth and probably sheathed in horn. 

 (S) The palatal area is very narrow in front and wide behind, 

 with strongly curved lateral boundaries. (6) The posterior 

 maxillary and palatal teeth are multiserial. (7) The rami of 

 the mandible are united in a long symphysis, behind which they 

 diverge widely, and the dentigerous edges are strongly concave 

 upwards as well as outwards. (8) The mandibular teeth in 

 front are set into a close, apparently continuous palisade, and 

 become distinct and conical only at the posterior end of the 

 series. (9) The fore-foot is remarkably short and stout, with 

 metacarpals of equal length. The relations ol Rhynchosatirus to 

 Hyperodapedon and Sphenodon were then dealt with, the first- 

 named being shown to occupy in some respects an intermediate 

 place between the two others. The skull of Rhynchysaiirus 

 resembles that of Hyperodapedon in its single anterior nasal 

 aperture, its premaxillary and mandibular rostral processes, and 

 in having more than one series of palatal teeth ; but in general 

 form and in the shape of the maxillae, palatal bones, and rami of 

 the mandible it departs far less from Sphenodon than Hypero- 

 dapedon does. Some comparisons of the limb-bones were also 

 made. The three genera mentioned were shown to form a 

 particular group, which, however, hal no claim to ordinal dis- 

 tinction, and appeared to form a family, Sphenodontidse, of the 

 Lacertilia, comprising two sub-families, Rhynchosaurinse (in- 

 cluding Rhyncliosaurus and Hyperodapedon) and Sphenodon- 

 tinae. The fact that in this Lacertilian group the highest known 

 degree of specialization, as shown in Hyperodapedon, was attained 

 as early as the Triassic epoch, showed that in Permian times, or 

 earlier, Lacertilia existed which differed less from Sphenodon 

 than either of the Rhynchosaurinte did. Not only was the 

 Lacertilian type of organization clearly defined in the Triassic 

 epoch, but it attained a degree of specialization equal to that 

 exhibited by any modern lizard. The reading of this paper was 

 followed by a discussion, in which the President, Dr. Geikie, 

 Prof Seeley, Mr. Lydekker, Prof. Boyd Dawkins, and others 

 took part. — On the rocks of the Essex drift, by Rev. A. W. 

 Rowe. — On Tertiary Cyclostomatous Bryozoa from New Zealand, 

 by Mr. Arthur W. Waters, 



Edinburgh. 



Royal Society, April i8. — Sir W. Thomson, President, in 

 the chair. — Prof. Rowland's photographs of the solar spectrum 

 were exhibited. — The President read a paper on ship-waves, 

 and another on the instability of fluid motion. Both papers 

 appear in the Phil. Mag. — Mr. D. S. Sinclair gave a communi- 

 cation on an experimental research in magnetism. — A paper by 

 Mr. A. H. Anglin on the summation of certain series of altern- 

 ants was submitted. — Prof Crum Brown read a paper by Mr. H. 

 Marshall on cobaltic alums. — Mr. G. N. Stewart submitted a 

 synopsis of researches on the effect produced on the polarization 

 of nerve by stimulation. 



May 2. — Sir Douglas Maclagan, Vice-President, in the chair. 

 ' — Prof. J. B. Haycraft read the third part (on the sense of 

 smell) of a paper on the objective cause of sensation. — Prof. 

 Crum Brown read a paper on the physics of noise. His object is 

 to investigate the various components which make up ordinary 

 noises, such as a hissing sound. — Prof. Dittmar and Mr. C. A. 

 Fawsitt communicated a paper on the physical properties of 

 methyl alcohol. — Prof Dittmar also discussed the instability of 

 the double salts of M"S04. R'2S04 + 6H2O of the magnesium 

 series. — Mr. J. Rattray described a diatomaceous deposit found 

 at North Tolsta, Lewis. 



Paris. 



Academy of Sciences, May 16. — M. Janssen in the chair. 

 — Obituary notices of the late M. Boussingault, member of the 

 Section for Rural Economy, who died on May 11, by MM, 

 Schloesing, Troost, and the President. — On some deviations 

 from the normal direction of sound calculated to render in- 

 effective the fog-signals and similar appliances employed in 

 navigation, by M. H. Fizeau. The paper, written with refer- 

 ence to some recent shipping disasters during foul weather, 

 shows on theoretical grounds that, the surface of the sea being 

 at times warmer than the surrounding atmosphere, the aerial 

 strata must in calm weather decrease in temperature upwards to 

 a certain height above sea-level. This occurs not only at night, 

 but also frequently during the day in foggy weather. Hence 

 the sounds of the fog-signa!s, intended to be propagated hori- 

 zontally, are necessarily affected by the differences of atmo- 

 spheric temperature, those nearest the surface of the water 

 acquiring greater velocity than those traversing the higher 

 strata. Thus is at times produced a sort of "sound mirage," 

 perfectly analogous to the well known corresponding phenomena 

 of light. Once the cause of the deviations is understood, the 

 means of counteracting them will easily suggest themselves. — 

 Effects of earthquakes on magnetic instruments, by M. Mascart. 

 The reports of magnetic disturbances received from various sta- 

 tions in France, England, Germany, Russia, and other European 

 countries, show great discrepancies as to the time and intensity 

 of the shocks ; but whether these discrepancies are to be attri- 

 buted to possible errors of observation, to the difference in the 

 character of the instruments, or to physical causes, cannot at 

 present be determined. If the cause of the disturbances is really 

 electric, its very mechanism is absolutely unknown. — Observa- 

 tions of Barnard's new comet, e 1887, made at the Paris Observa- 

 tory (equatorial of the West Tower), by M. G. Bigourdan. This 

 comet, discovered on May 12, at Cambridge, in the United 

 States, was seen at Paris on May 14, when it presented the 

 appearance of a round nebulosity of l' diameter, and of the 

 thirteenth magnitude, with considerable central condensation, 

 notwithstanding its slight altitude above the horizon. — On the 



direct determination of the differential coefficient — ^ , relative to 



dt 



saturated vapours, by M. A. Perot. It is shown that the 

 mechanical equivalent of heat may be determined by the well- 

 known relation — 



E ^ dt' 



which is obtained by applying to a liquid mixture and its vapour 

 the principle of equivalence, and that of Carnot. In order to 

 approximately determine this quantity, the author has under- 

 taken to measure on the same sample of pure ether, ac a tem- 

 perature of 30°, the different parameters entering into the pre- 

 ceding relation — m', u, L, and -^. To determine—^ he employs 



a special method, which enables him to measure separately the 

 two corresponding quantities dp and dt. The determinations 

 have been made for the temperatures 29' to 31° inclusive, within 

 which interval they may be represented by the formula — 



^ = 2-2750 -f (/- 29) 0-0834. 

 d t 



— Intertropical diurnal and annual variations of terrestrial mag- 

 netism (second note), by M. Ch. Lagrange. By comparing the 

 observations recorded at two stations on either side of and 

 e quidistant from the equator, such as Bombay and St. Helena, 

 Hobartown and Toronto, the author finds that there exists in the 

 atmos phere and in the earth a system of currents moving east 

 an d west, whose strata of greatest intensity penetrate the atmo- 

 sp here, descending in the hot season below the surface of the earth 

 a nd again rising in the cold season. This system seems to prove 

 the reality of Ampere's general system of currents extended to 

 the earth and the atmosphere. From this it also follows that 

 the existence of these aerial magnetic currents involves a diminu- 

 tion of temperature with elevation. Consequently these currents 

 are one of the factors, possibly the chief factor, in the thermic 

 system of the globe, so that a fundamental connexion exists 

 between meteorological phenomena and those of terrestrial mag- 

 netism.— On the reproduction of alabandine, by M. H. Baubigny. 

 By the process here described the author has obtained some 

 beautiful octahedric crystals, presenting all the characteristics of 

 alabandine (MnS) : the same crystalline form, colour, and 



