94 



NA TURE 



\_ISfov. 25, 1886 



Geological Society, November 3. — Prof. J. W. T»'lil> 

 F.R.S., Presiilent, in the chair. — Henry Howe Arnold-Bemro^e. 

 Richard Assheton, Francis Arthur Bather, Rev. Joseph Camp- 

 bell, M.A., John Wesley Carr, Thomas J. G. Fleming, Thomas 

 Forster, Edmund Johnstone Garwood, George Samuel Griffiths, 

 Dr. Frederick Henry Hatch, Ph.D., Robert Tuthill Litton, 

 Frederick William Martin, Richard D. Oldham, Forbes Rickard, 

 Albert Charles Seward, Herbert William Vintner, and Charles 

 D. Walcott were proposed as Fellows of the Society. — The 

 following communications were read : — On the skull and denti- 

 tion of a Triassic Saurian, Galcsaiirtts planiccps, Ow. , by Sir 

 Richard Owen, K.C.B., F. R.S. The author referred to a fossil 

 skull from the Triassic sandstone of South Africa, which com- 

 bined dental characters resembling those of a carnivorous mam- 

 mal with the cranial structure of a Saurian. The structure was 

 described .and figured in Owen's "Catalogue of the Fossil 

 Reptilia of South Africa," under the generic title of Gaksauriis, 

 as belonging to a distinct sub-order of Reptilia termed Therio- 

 lionlia. The characters of the sliuU and teeth of the original 

 specimen of Gulcsaunis have been brought to light by further 

 development. In both the type-specimen and that lately re- 

 ceived, the reptilian nature of the fossil is indicated by the single 

 occipital condyle and other features. The chief difference from 

 a mature male of a placental or marsupial carnivore is the evi- 

 dence of a primordial "gullet-tract." Further details as to the 

 structure of the skull were given, more especially with reference 

 to the orbits and nasals. The palatal region repeats the same 

 general characters as in previously described Theriodonts. The 

 angle of the jaw is not produced, as in the crocodile, beyond 

 the articular element. In general shape and bony strength the 

 mandible of GaUsaurus resembles that of a mammal. The 

 dentition is so inuch better preserved in the new specimen than 

 in the type Galesaur as to call for description and illustration. 

 In four of the upper molars the entire crown is preserved ; it 

 shows less length and greater breadth than appears in the pre- 

 vious restoration, is moderately curved externally, and triangu- 

 lar ; the base is flanked by a short cusp before and behind, and 

 the corresponding margins are finely crenulate, as in the molars 

 of Cynoiii-acon . The incisors are eight in number in both upper 

 and lower jaws, four in each premaxillary, opposed or partially 

 interlocking with the same number in each mandibular ramus ; 

 they have longish, slender, simple-pointed crowns. The canines, 

 one on each side of both upper and lower jaws, have the same 

 laniariform shape and size of crown as in the original fossil. In 

 the right maxillary bone the long deeply-planted root is ex- 

 posed ; the corresponding part of the lower canine is similarly 

 exposed in the left mandibular ramus. No trace of successional 

 teeth, as in ordinary Saurians, has been found. Both crocodiles 

 and alligators have two or more teeth of canine proportions ; but 

 the author shows how they differ from those of mammalian 

 carnivores and Gaksaiiriis. A similar character and disposition 

 of destructive canines is shown by the fossil jaws of the oolitic 

 great extinct carnivorous Saurians, e.g. Megalosaurus, In the 

 Triassic Labyrinthodonts the destructive and prehensile laniaries 

 would, by position, rank as incisors rather than canines. In 

 existing lizards the dental series has more unifonnity, and the 

 cement-clad roots contract bony union with the jaw-bone. In 

 GalesaiiiHs the teeth, besides being distinguished, as in mam- 

 mals, by their differential characters, are implanted freely in 

 sockets, the cold-blooded character being chiefly manifested in 

 the greater numljer of teeth following the canines, and in their 

 want of distinction. lastly, the author remarked on the earlier 

 reptilian character shown by the oolitic mammal Amphitheriiim, 

 and also by the existing Australian Myrmccobiiis. He speculates 

 on the degree of resemblance manifested by the teeth of the old 

 Triassic reptile of South Africa with the exceptional characters 

 of some of the low Australian forms of mammals. — The Cetacea 

 of the Suftblk Crag, by R. Lydekker, B.A., F.G.S. This paper 

 commenced with notices of previous contributions to the subject 

 by Sir R. Owen, Prof. Ray Lankester, Prof. Huxley, and Prof. 

 Flower. In the preparation of a catalogue of the specimens in 

 the British Museum, the author had had occasion to examine 

 the collection of Cetacea from the Crag, not only in that Museum, 

 but also in the Museum of Practical Geology, that of the Royal 

 College of Surgeons, and in the Ipswich Museum, besides visit- 

 ing the collections at Bnissels. In consequence, several addi- 

 tions to the fauna, and also numerous emendations of specific 

 names, were noticed in the paper now laid before the Society. 

 Prof. Ray I.ankester's views as to the Diestian affinities of the 

 English-Crag Cetacea were confirmed by this comparison. De. 



tailed notes on the specimens examined and the species identi- 

 fied were given. — On a jaw of Hyotherium from the Pliocene of 

 India, by R. Lydekker, B.A., F.G.S. Colonel Watson, the 

 Political Resident in Kattiawar, had recently sent to the author 

 a fragment of a left maxilla with the three true molars, from 

 Perim Island, in the Gulf of Cambay. The specimen belonged 

 to Hyotherium, and apparently to an undescribed species, the 

 differences between which and the several forms previously 

 known from various European and Asiatic beds were pointed 

 out. The author also called attention to the peculiar association 

 of types found in the beds of Perim Island, and to the affinitie-- 

 of the genus Hyotherium with the recent Sus and Dicotyles on 

 the one hand, and with the Upper Eocene Charopo'ainus on the 

 other. 



Physical Society, November 13. — Prof. Balfour Stewart, 

 President, in the chair. — In opening the proceedings, the Presi- 

 dent referred to the great loss which the Society had recently 

 sustained by the death of Prof. Guthrie, F. R. S., the founder of 

 the Society, and his predecessor in the chair. In the capacity 

 of Demonstrator, Prof. Guthrie contributed materially to the 

 success of the Society's meetings, and his decease is deeply re- 

 gretted. The President also announced that the Council were 

 considering what steps should be taken to commemorate the 

 late Dr. Guthrie, and that a circular containing their views 

 would be placed before the members in the course of a few days. 

 — The following papers were then read : — On the peculiar sun • 

 rise shadows of Adam's Peak, in Ceylon, by the Hon. Ralph 

 .\bercromby, F. R. Met. Soc. The author prefaced his descrip- 

 tion by an extract from a paper on the same subject by the Rev. 

 R. Abbay, read before the Physical Society, May 27, 1S76, in 

 which the explanation proposed is that the eftects are caused by 

 total internal reflection, as in ordinary mirage, the dift'erence of 

 air-density being, in this case, due to the lower temperature at 

 high altitudes. The author pointed out that Mr. Abbay neglects 

 the difference of density due to elevation, and that his own 

 thermometric observations disprove conclusively any idea of 

 mirage. The chief phenomena observed were : (l) the appear- 

 ance of a circular rainbow with spectral figures near the top of 

 the shadow of the peak ; and (2) a peculiar rising of the bow 

 and shadow, which seem to stand up in front of the observers. 

 Both these effects are traced to the existence of mist-clouds in 

 the vicinity of the shadow. Two dark rays or brushes were 

 seen to shoot outwards and upwards from the circumference of 

 the bow in directions nearly coinciding with the prolongations 

 of the edges of the shadow, when seen projected on the lower 

 mist-clouds, but the author does not attempt to explain this 

 phenomenon. On one occasion a second and outer bow was 

 seen. The times during which the phenomena were visible were 

 too short to permit sextant observations being taken, but the 

 di.ameter of the inner bow was estimated at S° to 12'. A totally 

 distinct kind of shadow is sometimes seen from Adam's Peak 

 just before, and at the moment of sunrise, which seems to stand 

 up against the distant sky. The author found a similar effect 

 at Pike's Peak, Colorado, which is visible only at sunset. Mr. 

 G. Griffiths remarked that he had often seen similar appearances 

 in Switzerland. In answer to questions by the President and 

 Prof. S. P. Thompson, the author said the reason why the 

 shadows were seen from Adam's Peak at sunrise, and from 

 Pike's Peak at sunset, was that the configuration of the land on 

 the west side of the former was similar to that on the east side 

 of the latter, both being low, whereas the opposite sides were 

 high, and therefore unsuitable for showing the phenomena. In 

 .all cases he believed the appearances were due to the shadows 

 being projected on clouds of suspended matter in the air at 

 various altitudes. He had not noticed whether the colours were 

 reversed in the second bow seen from Adam's Peak, but ob- 

 served that this bow nearly, but not quite, touched the inner 

 one. — Note on the internal capacity of thermometers, by A. 

 W. Clayden, M.A. (Read by Prof. Reinold, Secretary.) The 

 author proposes to determine the volume, V, of the mercury by 

 measuring the capacity, c, of a detached piece of the same tube 

 of known length, and thence inferring the volume of / degrees 

 of the thermometer tube, the length of which is equal to that 

 of the piece of tube taken. By assuming the value of a (the 

 coefficient of apparent expansion of mercury in the particular 

 kind of glass) to be known, the volume of the mercury in the 

 thermometer can be calculated, since c = t a V. Prof. Riicker 

 remarked that there were often considerable differences in the 

 sectional area of different parts of the same tube, and hence the 



