Dec, 2, 1875] 



NATURE 



99 



and the peculiar respiratory organs 'of birds, are class characters, 

 any animal would be a member of the class Aves which pos- 

 sessed them ; and since the form of skull, of vertebrae, of the 

 carpus and tarsus are ordinal characters m the existing sub-class 

 of birds, they will not necessarily be foimd in an extinct sub-class 

 or order of Aves. He then showed that Pterodactyles have the 

 brain identical with the bird's brain in every detail ; and the 

 pneumatic perforations of the bones for the prolongation of air- 

 cells from the lungs into the bones were identical in both types 

 and are found in no other group of animals. Hence it was 

 concluded that, judged by class characters, Ornithosaurs must 

 be placed in the class Aves. The author then gave an analysis 

 of the characters of the Omithosaurian skeleton. In the skull, 

 he thought that the bone hitherto named post-frontal is the quad- 

 rato-jugal, and that although the malar bone meets the quad- 

 rate bone, there are no reptilian features in the skull, and no- 

 thing which is inconsistent with the Avian organisation. The 

 vertebral column is the most reptilian part of the skeleton 

 in being procoelous, but the fore limb was shown to be constructed 

 on the AN-ian plan ; the carpus being nearly identical in both 

 groups ; while the elongated finger for flight was proved by its 

 carpal articulation to be the index finger as in birds ; and in one 

 Pterodactyle it contained two phalanges, as in birds. The petagial 

 membranes of the Pterodactyle were also shown to be extensions 

 of the similar membranes of birds. The characters of the pelvis 

 and hind limb were less unlike those of a bird than had been 

 supposed, the tibia terminating distally in a trochlear end formed 

 as in birds by the anchylosed proximal tarsal bone. From the 

 whole skeleton (excluding the evidence of the cerebral and 

 respiratory characters) the author concluded that it is impossible 

 on morphological grounds to exclude the Omithosauria from the 

 Avian class, and that their resemblances to reptiles are not more 

 important than their resemblances to mammals. 



Geological Society, Nov. 17.— Mr. John Evans, V.P.R.S., 

 president, in the chair. — Mr. Robert Elliott Cooper, C.E., i, West- 

 minster Chambers, Victoria Street, S.W. ; Mr. George Fowler, 

 Assoc. Inst. C.E., Basford Hall, Nottinghamshire; and Mr. 

 William Frecheville, Assoc. Royal School of Mines, 51, Scarsdale 

 Villas, Kensington, W., were elected Fellows of the Society.— 

 On a new modification of Dinosaurian Vertebrae, by Prof. 

 Richard Owen, F.R.S. The peculiar modification of the Dino- 

 saurian vertebra noticed by the author occurs in Tapinocephalus 

 Aiherstonii and Pareiosaurus bombidens. In the dorsal vertebrae 

 of the former the centra are nearly flat on both fore and hind 

 surfaces, a structure to express which the author proposes the 

 term " amphiplatyan." The hind surface is very slightly the 

 more concave. The middle of each surface is pierced by a small 

 foramen leading into a cylindrical canal, first slightly expanding 

 and then rapidly contracting to a point, which meets the apex of 

 the similar hollow cone coming from the opposite surface. Simi- 

 lar characters were observed upon the free surface of the anterior 

 sacral and upon that of the posterior of four anchylosed sacrals. 

 The dorso- lumbar vertebrae of the Pareiosaurus had centra rela- 

 tively longer than those of Tapinocephalus. Their articular sur- 

 face is subundulate, convex along a fourth of the periphery, 

 concave at the centre, where there is an excavation corresponding 

 to that in Tapinocephalus, but a relatively wider aperture, a 

 lather more constricted canal, a shorter terminal cone, and an 

 interval of osseous tissue separating the apices of the cones from 

 the fore and hind surfaces. In what is probably the first cervical 

 vertebra of the same Dinosaur, the centrum is so concave on 

 both surfaces as to become amphiccelian. In these unossified 

 tracts of the middle of the centrum in the two genera above 

 mentioned the author sees indications of a persistent trace of the 

 primitive "chorda dorsalis ;" and he calls attention to the resem- 

 blance thus set up between these probably Triassic Dinosaurs 

 and the lower Ganocephalous reptiles of the Carboniferous series, 

 in which, however, the vertebral centra are more widely per- 

 forated.— On the presence of the Forest-bed Series at Kessing- 

 1 land and Pakefield, Suffolk, and its position beneath the Chilles- 

 ford Clay, by Mr. John Gunn. In this paper the author 

 described a section from the cliff at Kessingland and Pakefield, 

 from the examination of which he arrived at the conclusion that 

 the Forest-bed series underlies the Chillesford Clay and sands. 

 At the foot of the cliff there is an estuarine deposit forming the 

 soil of the Forest-bed, consisting of blue clay and gravel, the 

 "Elephant-bed" of the author's former paper. Above this is 

 the Forest-bed, cotaining large stools and stems of trees, but no 

 fossil bones. This is followed by a fresh-water deposit, consist- 

 ing of black soil with fresh- water shells, corresponding to a simi- 



lar bed at Mundesley and Runton known as the " i/«w-bed," 

 and including the " Rootlet-bed " of oozy clay, regarded by Mr, 

 Prestwich as an indication of the forest. The author considers 

 the supposed rootlets to represent brushwood which succeeded 

 the true forest. Above this come Fluvio-marine deposits, in 

 which Cragshells occur, although but rarely. To this division 

 the author was inclined to refer the Norwich Crag, which at 

 Bramerton underlies the next division, regarded by.the author as 

 the Chillesford Clays and Sands. Of the overlying deposits the 

 first is supposed to be the " Pebbly bed " by the author ; it has 

 been regarded as Middle Drift, and the uppermost is Upper 

 Botilder-clay. The paper was illustrated by the exhibition of a 

 fine series of bones, chiefly Cervine, from the lowest deposit 

 noticed by the author. 



Physical Society, Nov. 27.— Prof. G. C. Foster, F.KS,, 

 vice-president, in the chair. — The following candidates were 

 elected members of the Society : — Prof, Osborne Reyno'ds, 

 M.A., Prof. H.J. Smith, M.A., LL.D,, Prof. R. B. Clifton, 

 M.A., F.R.S., C. Busk, J. Thomson, J, W. W. Waghom, W, 

 Esson, M.A,, F,R.S., F. W. Bayly, and Prof. R. W. Emerson 

 Mac Ivor, — Prof. Guthrie briefly described Dr, Kerr's recent 

 experiments to show that glass, resin, and certain other 

 substances exhibit a depolarising effect when under the influence 

 of powerful electrical tension, and he exhibited the arrangement 

 of apparatus employed in the research. He also showed certain 

 experiments connected with the investigation, — Dr. Guthrie then 

 made a communication on "Stationary Liquid Waves," in con- 

 tinuation of that which he made to the Society in June last. If 

 water in a cylindrical vessel not less than 9 inches in diameter be 

 agitated by depressing and elevating a flat circular disc on its 

 surface at the centre, a form of oscillation is set up which the 

 author terms "binodal," He finds that these fimdamental un- 

 dulations in an infinitely deep circular vessel are isochronous with 

 those of a pendulum whose length is equal to the radius of the 

 vessel, and further, a fact which is extremely interesting, that 

 the motions of the pendulum and water keep together throughout 

 their entire paths. An arrangement was exhibited fnr experi- 

 mentally demonstrating these facts. To the upper end of a 

 short pendulum with a heavy adjustable bob is attached a card- 

 board sector in the plane of vibration of the pendulum. A silk 

 thread, attached to the edge of this sector, carries a small paraffin 

 disc which rests at the centre of the surface of the water con- 

 tained in a cylindrical vessel. The pendulum-length is adjusted 

 until the motion of the disc is isochronous with that of the water 

 when the two are not in contact. Two other forms of motion 

 may be produced in cylindrical vessels, namely (i), by alternately 

 compressing and extending opposite ends of a diameter as in the 

 motion of a bell — this gives two diametral nodes at right angles 

 to each other ; and (2), by rocking the vessel, which gives a 

 single diametral node. Each of these has its own period of 

 vibration, the last being the slowest. They may be super- 

 imposed on each other, and a rotation of the water, however 

 great, does not interfere with their formation. In rectangular 

 troughs a binodal and a mononodal wave system may be esta- 

 blished. The former is induced by raising and depressing a 

 wooden lath at the middle of the surface, and the latter by 

 tilting, Binodal vibration in a circular trough may be compared 

 with a vibrating pair of triangular laths, and in rectangular 

 troughs to the balancing of two rectangular laths. In this latter 

 case the nodes are at \ of the trough length from each end. 

 Some discrepancies are met with when we compare times of 

 vibration in rectangular troughs of various lengths, and these are 

 due to a scraping action which takes place against the ends of 

 the vessel. The result of the experiments on binodal motion in 

 rectangular vessels is to show that the undulations are isochronous 



with the oscillations of a pendulum whose length is ^ times that 



of the trough. The chief points in connection with this subject 

 to which the author referred as still requiring explanation, are : 

 (I) Why are the motions pendular ? (2) How is it that in cir- 

 cular binodal motion the times are identical with that of a pen- 

 dulum of the given length ? and (3) What is the mathematical 

 connection between the individual motion of each particle and 

 that of the mass? Mr. Lodge thought that valuable results 

 might be obtained by treating the mass of moving water as a 

 penduUim with two bobs oscillating about the node. This 

 might be specially useful with small oscillations, when the surface 

 is practically plane. 



Anthropological Institute, Nov. 23.— Colonel A, Lane 

 Fox, F.S.A., President, in the chair. The President read a full 



