70 



NATURE 



[May 19, 1892 



in which he recommended the illumination of the drawing by a 

 powerful lamp, and the testing of the drawing by a slight change 

 in the position of the paper, so as to compare side by side the 

 drawing made and the camera lucida outline. Dr. Giltay 

 stated he had succeeded in drawing objects magnified 2500 

 times. Mr. A. D. Michael thought the method of comparison 

 would be likely to produce distortion. — Prof. Bell said a note 

 had been received from Mr. J. C. Wright on some rotifers 

 which he had found attached to a newt. The accompanying 

 drawings did not render it sufficiently clear that what he had 

 found were really rotifers, and he suggested they were Vorticellre. 

 — A note from Mr. W. M. Osmond was also read, descriptive 

 of a new cheap photomicrograpliic stand. Dr. VV. H. Dallinger 

 thought that though it might be useful for low-power work, he 

 doubted if it would be of value for high or even moderate 

 powers. He should be afraid that there would be too much 

 vibration. Mr. C. L. Curties said he should be sorry to use it 

 for anything beyond a half-inch objective. 



Geological Society, April 27.— Prof. J. W. Judd, F.R,S., 

 Vice-President, in the chair. — The Chairman announced that 

 the Organizing Committee of the International Geological 

 Congress have arranged to convene the sixth meeting of the 

 Congress at Ziirich, about the commencement of September 

 1894. Any communications should for the present be addressed 

 to Prof. E. Renevier, University, Lausanne.— Prof. W. C. 

 Williamson, F.R.S., exhibited the following specimens : slab 

 of Carboniferous Limestone from Bolland, illustrating the 

 passage of a foraminiferal ooze into crystalline calcite ; 

 Asteropeden Orion, Forbes, from the Kellaways rock, near 

 Pickering, Yorkshire ; and made the following remarks : — The 

 specimen before me is a slab of Carboniferous Limestone from 

 the Bolland district of West Yorkshire. In its centre is a 

 magnificent section of a large Nautilus — beautiful as a fossil, 

 but still more important because of what it teaches. Its large 

 terminal chamber is filled with foraminiferal ooze, the com- 

 ponent objects of which are almost as perfect as when the 

 organisms were living. The surrounding limestone is chiefly in 

 an amorphous state ; but it contains innumerable evidences that 

 it also consists of foraminiferal ooze, largely reduced to the 

 amorphous state by the agency of carbonic acid, now known to 

 be so abundant in the depths of the ocean. The action of this 

 acid upon the minute calcareous shells necessarily converted the 

 water into a solution of carbonate of lime. In this state it 

 percolated by osmosis through the shell of the Nautilus, 

 penetrating its closed chambers, which it gradually filled with 

 calcareous spar. The specimen is thus an epitome, within its 

 limited area, of what has taken place on a gigantic scale in the 

 deep sea. We have here first the organic mass, next its 

 conversion into amorphous limestone, and lastly the production 

 of the crystalline state of the same, so frequently seen filling the 

 interiors of fossils. The second object is i the original type- 

 specimen of Forbes's Asteropeden Orion, from a sandstone bed 

 of the Kellaways rock in the neighbourhood of Pickering, in 

 Yorkshire. This starfish had lived upon and became buried in 

 a sandy matrix which contained no lime. When the rock was 

 split open, the space originally occupied by the starfish was 

 hollow ; the sand contained no soluble material, like that which 

 filled the chambers of the Nautilus. But in the lowest beds of 

 the Coralline Oolite at Filey Brigg, on the Yorkshire coast, we 

 long ago found another species of starfish closely allied to the 

 Pickering species. This was embedded in calcareous stone, 

 which had once in all probability been foraminiferal ooze, and 

 the processes which filled the chambers of the Nautilus also 

 filled the cavity left by the decay of the starfish with crystalline 

 carbonate of lime. These specimens, studied collectively, 

 illustrate two of the most important and common of the 

 processes by which the mineralization of fossil remains has been 

 effected. — The following communications were read : — Notes on 

 the geology of the Northern Etbai or Eastern Desert of Egypt, 

 with an account of the emerald mines, by Ernest A. Floyer. 

 The principal feature in the district is a long ridge of igneous 

 upthrust running north north-west and south-south-east, in 

 which porphyry rises into lofty peaks, whilst the lower parts are 

 formed of granites and sedimentary rocks. To the west of the 

 watershed, sedimentary rocks occur dipping slightly to the west. 

 The following succession of rocks in descending order is given by 

 the author: limestone, sandstone, clay, " cataract "-rock (cor- 

 responding to the Stock-granit of Walther), and compact hard 

 granite. The sedimentary rocks are frequently metamorphosed, 

 and the author states that every stage of metamorphism is 



NO. II 77, VOL. 46] 



shown, from sandstone to compact green granite. The blue 

 clay shows various kinds of metamorphism, and forms the 

 pistachio-breccia containing topazes, and the mica-schist, mica- 

 slate, and talcose blue clay of the mass of Zabbara containing 

 emeralds. The author discusses certain theoretical questions, 

 and considers that the erosion of the valleys does not indicate 

 the existence of a greater rainfall than the present one. He 

 concludes by giving an account of the emerald mines. The 

 reading of this paper was followed by a discussion, in which 

 Prof. Hull, Prof. Le Neve Foster, Mr. Rudler, Mr. J. W. 

 Gregory, and Dr. Blanford took part.— The rise and fall of Lake 

 Tanganyika, by Alex. Carson (communicated by R. Kidston), 

 In this paper attention is called to certain recorded discrepancies 

 concerning the discharge of Tanganyika by the Lukuja. It is 

 suggested that the rise of the lake is due to the blocking-up of 

 the river by vegetation, assisted by silting during the first rains, 

 whilst the fall is produced by the destruction of the barrier 

 formed in this manner. 



Zoological Society, May 3.— Prof. W. H. Flower, F.R.S., 

 President, in the chair.— The Secretary read a report on the 

 additions that had been made to the Society's Menagerie during 

 the month of April, 1892, and called attention to a finely- 

 marked Owl {Pseudoscops gratnmieus) from Jamaica, presented 

 by the Jamaica Institute, being the first example of this Owl 

 that has reached the Society. — Mr. Sclater exhibited and made 

 remarks on a fine specimen of the egg of ALpyornis, the extinct 

 giant bird of Madagascar, obtained from Southern Madagascar, 

 and brought to this country by Mr. Pickersgill, H.B.M. Vice- 

 Consul at Antananarivo. — Mr. Oldfield Thomas read a paper 

 on the probable identity of certain specimens formerly in the 

 Lidth de Jeude collection, and now in the British Museum, 

 with those figured by Albert Seba in his "Thesaurus" of 

 1734. — Mr. F. E, Beddard read some notes on various species 

 of aquatic Oligochsetous Worms that he had lately had an 

 opportunity of examining. Amongst these was a new form 

 allied to Acanthodrilus from the saline waters of the Pilcomayo, 

 discovered by Mr. Graham Kerr during the Pilcomayo expe- 

 dition. — Dr. Hans Gadow read a paper on the systematic 

 position of Notorydes iyphlops, the newly-discovered Mammal of 

 Central Australia, and came to the conclusion that this 

 anomalous form should stand as a distinct family of Polyprotodont 

 Marsupials, allied to the Dasyuridae and the Peramelidse. — A 

 communication was read from Captain H. G. C. Swayne, R.E., 

 containing field-notes on the Antelopes of Northern Somali-land. 

 — Mr. W. Schaus read the second portion of his descriptions 

 of new species of Lepidoptera Heterocera from Brazil, Mexico, 

 and Peru.— Mr. W. L. Sclater read some notes on certain 

 specimens of Frogs in the Indian Museum, Calcutta, and gave 

 descriptions of several new species based upon some of these 

 specimens. 



Entomological Society, May 11.— Frederick DuCane 

 Godman, F.R.S., President, in the chair. — The President an- 

 nounced the death, on May 4, of Dr. C. A. Dohrn, of Stettin, one 

 of the ten Honorary Fellows of the Society. Mr. Stainton, F. R. S. , 

 expressed regret at the death of Dr. Dohrn, whom he had known 

 for a great number of years, and commented upon his work and 

 personal qualities. — Dr. D. Sharp,iF.R. S., exhibited drawings of 

 the eggs of a species of Hemiptera, in illustration of a paper read 

 by him before the Society ; and also a specimen of a mosquito 

 from the Amazon district, with the body., legs, and palpi fur- 

 nished with scales as in Micro-Lepidoptera. — The Rev. Canon 

 Fowler, on behalf of Mrs. Venables, of Lincoln, exhibited 

 cocoons of a species ol Bombyx from Chota Nagpur, India; also 

 the larvae-cases of a species of Psychidse, Cholia a-ameri, from 

 Poona, India ; and a curious case, apparently of another species 

 of Psychidse, from the island of Likoma, Lake Nyassa. — Mr. 

 F. W. Frohawk, on behalf of the Hon. Walter Rothschild, 

 exhibited a specimen of Pseudacrma miraculosa mimicking 

 Danais chrysippus ; also a specimen of the mimic of the latter 

 — Diadema misippus — and read notes on the subject. — Mr. C. G. 

 Barrett exhibited, and commented on, a long series of specimens 

 of Melitcea aurinia (arteniis) from Hampshire, Pembrokeshire, 

 Cumberland, and other parts of the United Kingdom ; also a 

 long and varied series of Coremia fluduata. — Mr. H. Goss 

 exhibited, for Mr. W. Borrer, Jun., of Hurstpierpoint, a photo- 

 graph of a portion of a nest of Vespa vulgaris which had been 

 built with the object of concealing the entrance thereto and pro- 

 tecting the whole nest from observation. He also read notes on 

 the subject, which had been communicated to him by Mr. Borrer. 



