Oct. 24, 1872] 



NATURE 



527 



This arrangement so far performs perfectly in all but one 

 particular. It throws a strong beam of light constantly upon 

 the four prisms//, and illuminates the lines well ; but although no 

 direct light can enter into the field from the mirror placed so far 

 out of the cone of rays from the objective^ still the light thrown 

 against the side of the eye-piece tube is sufficient to completely 

 destroy the effect of this illumination. The difficulty, however, 

 has been completely remi:)ved in this way : — ■ 



I should first mention that the eye-piece or micrometer tube 

 is made double, an outer parallel tube and an inner taper one, 

 and it is between these two that it is required that the light 

 should be brought to the four prisms or micrometers, any light 

 shining into the inner tube doing mischief by injuring the black- 

 ness of the field. 



On the lens used to give a slight convergence to the liglit is 

 placed a circular opaque disc, o, of a certain size easily ascertained. 

 A lens, I, of a suitable focus being then placed near the reflector, 

 an image is formed of that opaque disc just over the eye-piece 

 tulie at X, and of such a siz.e, when properly adjusted, that no light 

 can possibly enter the inner tube 



Thus, while not a single ray of light can by any possibility 

 enler the inner tube, a flood of light is sent down between the 

 inner and outer tubes, and directed upon the four prisms in 

 whatever angular position they may be. 



It only remains to say that both the intensity and colour of 

 the light for both characters of the il'umination are under com- 

 plete control of the obser\'er while actually observing. 



One other matter is perhaps wortliy of note. 



The w.ant of a convenient method of mapping nebulx or faint 

 stars by a reticulated diaphragm of bright lines in the field of view 

 has long been felr, and the various methods of using diamond 

 scratches on glass or illuminated lines are subject to objection, 

 and troublesoine to manage. A simple method of using an 

 image of such a diaphragm instead of the actual diaphragm itself 

 here suggests itself 



Referring to the portion of the rays used for bright field illu- 

 mination, and shown in Fig. i, suppose the small diagonal mirror, 

 r', to be replaced by an equally small prism having such a convex 

 power that it forms an image of any object at the end of the 

 declination axis exactly in the same plane as the linage formed by 

 the objective — then any kindjof reticulated diaphragm of bright 

 lines on dark ground can be placed on the end of the declination 

 a.xis which would have a suitably prepared carrier for them, and 

 their image would be seen in the field of the telescope of any 

 colour and any intensity desired. 



SCIENTIFIC SERIALS 

 The Scottish N'aturalist for July is rich in articles of interest, 

 mostly brief, and chiefly relating to Entomology and Ornithology. 

 Many deserve notice, but we have been especially interested in 

 one on the nest of Foniiici nifa and its inhabitants by the editor. 

 Dr. Buchanan White. 



In yhe yournal of Botany (or August, Dr. Trimen describes 

 and draws the genuine Kmiunaihis clucrophyllos Linn, which 

 has been detecied in Jersey, but was not heretofore known 

 as a native of Britain. Dr. Hance describes a new species of 

 Iris, /. tomiolopha. The Rev. J. M. Crombie contributes some 

 notes on the Lichens in .Sowerby's Herbarium. — In the September 

 number. Dr. Hance describes another new species belonging to 

 the Bignoniacea;, SpiU/io./cii ciiuda-fLH)ia. Mr. T. R. A. Briggs 

 contributes Notes respecting some Plymouth plants, and Dr. A. 

 Ernst Notes on a small collection of Alpine plants from the 

 summit of ?\aiguta in the mountains of Caracas. — The first 

 article in the October number is Mr. Ilayne's paper, read at the 

 Brighton meeting of the British Association on the Flora of 

 Moab. Mr. J. G. Baker, who has paid great attention to the 

 Liliacex, has a monograph of the two genera Dasylirioii and 

 Beauccirnea. Another British Association paper, Mr. Hemsley's 

 Summary Analysis of the Phanerogamic and Fern Flora of 

 Sussex, is reprinted. The Rev. E. O'Meara contributes a con- 

 tinuation of his recent researches in the Dialomacece; and the Rev. 

 J. M. Crombie, a description of a new erratic British Fanndia. 

 Mr. Leo Grindon forwards a suggestive paper on the non- 

 occurrence near Manchester of certain common British plants. 



The last part of the Proceedings of the Swedish Academy of 

 Sciences (or 1871 (Ofversigt af Kongl. Veterskaps-Akademiens 

 Fcirhandlingar, Arg. 28, No. 7), opens with a notice by Prcjf. 

 Lilljeborg of the occurrence of a South European species of 

 Bleak (Leueaspius delineattis, Heckel) at Landskronain Scania. — 



The same author has also a notice of the occurrence of I.imnadia 

 gigas (Hermann) in Sweden, which will prove of considerable in- 

 terest to the student of Crustacea, as in it he gives a very detailed 

 description, illustrated with good figures, of the structure of this 

 curious species, and also gives a list of the other species of Phyllo- 

 poda, six in number, which inhabit Scandinavia. Prof Lillje- 

 borg is inclined to identify this species with the Monoailus lenti- 

 eiilaris of Linnaeus. — Prof Nordenskiold publishes a short paper, 

 containing a table, on the fixed and variable atomic volumes of 

 simple bodies. — The Swedish expedition to Greenland of the 

 year 1870 originates two papers, namely, a valuable essay on the 

 Phanerogamic flora of Disco Bay and Auleitsivik Fjord by Prof. 

 S. Berggren; and a series of calculations of geographical positions 

 worked out by M. E. Jaderin. — M. L.K. Daa discusses the 

 origin and meaning of the name of Grumant applied by the 

 Russians to .Spitzbergen, and cited as an evidence of the inde- 

 pendent discovery of that inhospitable land by the Russians ; 

 M. Daa states that Spitzbergen was named East Greenland by its 

 earliest English and Dutch visitants, and he maintains that 

 "Grumant" is merely a corruption of "Gronland." — Mr. H.D.J. 

 Wallengren publishes a Contribution to the knowledge oftheLepi- 

 dopterous fauna of the island of St. Bartholomew in the West 

 Indies. He gives a list of 34 species belonging to various 

 families from the Rhopalocera to the Crambida?, with remarks on 

 their characters and distribution. Three species are described as 

 new, namely, Graphiphora bartholemica, Micra Stdlii, and 

 Palthis U^alkeri. — M. L.J. Igelstrom notices the discovery of 

 s.andstone in situ in the Gefleborg district. 



SOCIETIES AND ACADEMIES 



PHtLADELPHIA 



Academy of Natural Sciences, April 9. — Prof. Leidy 

 directed attention to some fossils upon which he made the 

 following observations : — Several teeth and jaw fragments 

 from the Loup Fork of the Niobrara River, Nebraska, 

 obtained by Prof. Hayden, appear to indicate a large species 

 of Felis, not previously described. The most characteristic 

 specimen consists of an upper sectorial molar about as large 

 as that of the Bengal tiger, and consequently much too large for 

 either of the largest American cats, the panther and the jaguar. 

 It is as much too small to have pertained to the American lion, 

 Felis atro.x, for its breadth is but slightly greater than that con- 

 tained in the lower jaw, from which the latter was described. 

 Breadth of the crown of the tooth is I5fr lines ; its thickness in 

 front S lines. The measurements in the corresponding teeth ofa 

 Bengal tiger are, 16 lines in breadth, and 7! lines in thickness iu 

 front. Tlie form of the fossil tooth is the same as in the other 

 feline species. The extinct species may be named Felis atigiistus. 

 A distal extremity of a humerus, from the Niobrara River, about 

 the size and construction of the corresponding part in the Bengal 

 tiger, may belong to this species. Another fossil, consisting ofa 

 detached body of a vertebra, apparently indicates an extinct 

 reptile allied to Pleswsaunis and Discosaui-iis. The specimen, 

 recently received from Prof Hayden, was obtained in 1870, on 

 Henry's Fork of Green River, Wyoming. It is free from at- 

 tached matrix, and was the only specimen pertaining to the 

 animal which was found. It probably belonged to a formation 

 of earlier date than that of the same locality, which has yielded 

 other fossils previously described. The vertebra is from the base 

 of the tail, and is much shorter in relation to its other dimensions 

 than in Flesiasanrus or Diseosanrns. The extremities are con- 

 cave, and encircled near the margin of the articular surfaces with 

 a narrow groove. Posteriorly there are two larger articular facets, 

 as widely separated as the bone would permit, for the junction of 

 a chevron. Anteriorly there are no marks of chevron attach- 

 ment. The roots of strong transverse processes or diapophyses 

 project from the sides of the body just above the middle. The 

 neural arch was completely co-ossified with the body, leaving no 

 trace of its earlier separation. The breadth of the body is 23 

 lines, its depth 19 lines, and its length I inch. Viewing the 

 specimen as probably representing a genus different from those 

 mentioned, I propose to name it with the species as Oligosimus 

 granduviis. Another fossil is r, remarkable specimen, obtained 

 by Prof. Hayden in the " Black Foot Country " at the head of 

 the Missouri River. It looks as if it had formed part of the 

 dermal armour of some huge saurian or perhaps of an armadillo- 

 like animal. It is imperfect, and looks as if it were half broken 

 away. In its present state it is hemiovoid, about two inches 

 in diameter, concave below and convex above, where it is 



