I go 



NATURE 



\_Dec. 20, 1883 



In a natural classification cif t'ne genus the most fundamental 

 separation appear, to me that along the duttsd line ab dividing 

 the non-stridiilating from the stridulating species. This division 

 once made, the stridulating species fall into two natural sub- 

 divisions, expressed in the table by the line c d, which divides 

 the brevicorn from the longicorn forms. 



I think the niDit convenient classification is obtained by 

 dividing the species along the two lines ff/', ci/into three sub- 

 genera, one identical with the "Languustes longicornes " of 

 Milne-Edwards, the others formed by splitting up the " Lan- 

 goustes ordinaires " into species with and species withiut a 

 stridnlating organ. 



The following table embodies the proposed arrangement : — 

 Genus Palinurus, Fabr. 



A. Stridulating organ absent ; rostrum well developed, clasped 



by paired pedate jirocesses of the antennulary sternum ; pro- 

 cephalic processes present ; coxocerites imperfectly fused ; 

 antennulary (lagella short (sub-genus Jasus, T.J. P.). 



P. iaiandii, P. cdwardsii, P. hiigdlii, P. tumidus. 



B. Stridulating organ present ; rostrum variable, bnt rarely 



(? never) as well developed as in (A) ; pedate clasping pro- 

 cesses absent ; procephalic proces-es absent. 



a. Antennulary sternum narrow below, bases of anten- 

 nules being hidden, in a view from above, by bases 

 of antennie ; coxocerites imperfectly fused; anten- 

 nulary flagella short (sub-genus Palinurus). 



a. Rostrum well developed, covering ophthalmic 



sternum. P. tiigonus. 



p. Rostrum reduced to a small spiniform tubercle; 

 ophthalmic sternum uncovered. 



P. vulgaris. 

 l>. Antennulary sternum broad below, bases of antennules 

 being visible from the dorsal aspect ; coxocerites per- 

 fectly fused ; antennulary flai;ella long (sub-genus 

 Panulirus, Gray ; Senex, PfeifTer). 



P. interrupt us, P. fasciatiis, &c. , &c. 

 Dunedin, N.Z., October 2 T. Jeffery Parker 



SCIENTIFIC SERIALS 



Bulletin of the Belgian Royal Academy of Sciences and Btlles 

 Lettres, October 4. — Obituary notices of the late M. Joseph 

 Plateau, by MM. i)uprez, Valerius, and Liagre. — Second com- 

 munication on the discovery of the fossil iguanodon at Bernis- 

 sart, by P. J. Van Beneden. — Researches on the absolute furce 

 of the muscles of the Invertebrates ; Part I. Absolute force of 

 the adductor muscles in the lamellibranch molluscs (four illustra- 

 tions), by M. Felix Plateau. — Note on a new optical illusion, by 

 H. Valerius. — Remarks on the action of lightning conductors 

 constructed on the Melsens system, by H. Valerius. — Arith- 

 metical and algebraic theorems, by E. Catalan. — Note on tlie 

 pelvisternum in the Edentates (ten illustrations), by Prof. Paul 

 Albrecht. — Funeral oration of M. Henri Conscience in Flemish 

 and French, by M. Pierre Willems. — Memoir on the biblio- 

 graphy of international law before the publication of Grotius's 

 "Jus belli et pacis " (1625), by Alphonse Rivier. — Confession 

 de Poete, a poem, by Charles Potvin. — Some traits of the .social 

 life of the Celestial Empire. How history is manufactured in 

 China; civil and military decrees, by Ch. de Harlez. — Reports 

 on the competitive ]3apers sent in on the subject of Gretry, a 

 critical study of his life and works. The prize, a gold medal 

 of the intrinsic value of 32/., was awarded to M. Michel Breuet 

 of Paris. — Reports on the competitive papers received on the 

 subject of realism, its definition and influence on contemporary 

 painting. The essay by M. Henry Hymans, a member of the 

 Academy, was pronounced the best. But the prize, also a gold 

 medal worth 32/., was not awarded to him, owing to his failure 

 to comply with the conditions of the competition. — Discourse 

 on the annual exhibition of paintings, by M. Fetis The prize 

 of a thousand francs for the best cartoon on the subject of help 

 for the wounded on the battle-field, as a decorative piece for a 

 military hospital, was awarded to M. Henri Evrard, of Saint 

 Gilles-lez-Bruxelles. 



SOCIETIES AND ACADEMIES 



London 

 Royal Society, December 6.— "The Wavelengths of A, a, 

 and of some Prominent Lines in the Infra-Red of the Visible 

 Spectrum." By Capt. Abney, R.E., F.R.S. 



M. Fievez has recently sent the author a map of the solar 

 spectrum from C to A ("Aunales de I'Observatoire Royal de 

 Bruxelles," nouvelle serie, tome v.) inclusive, and as part of tliis 

 region is one which he is measuring, he examined the new publi- 

 cation with great interest. Photography and eye measurements 

 do not coincide in the detail of the grouping of the little a grou)>, 

 or from there as far as A, and A itself is shown by M. Fievez's 

 map as wanting in some details which appear in the photographs. 

 The wave-lengths of the different lines from above " « " to A 

 are not tho e given by Fievez, when comparison photographs o 

 the 1st order of the red with the 2nd of the ultra-violet weref 

 taken on the same photographic plate, or when the 2nd order of 

 the red is compared with the 3rd order of the green taken in a 

 similar manner. Prof. Rowland's concave gratings were em- 

 ployed for this compari'on. Cornu's map was used as a reference 

 for the ultra-violet wave lengths, and Angstrom's map for those 

 in the blue and green. 



The determination of A has been made by Mascart, Smythe, 

 and others, besides Angstrom and Langley, with discordant re- 

 sults. The above may be taken as accurate, as are Cornu's 

 and Angstrom's maps. 



The foUow-ing are wave-lengths of some of the principal lines 

 in the infra-red. The scale numbers refer to the author's map of 

 the infra-red, which is published in the Phil. Trans., Part II., 



Mathematical Society, Decemberi3. — S. Roberts, F.R.S., 

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

 bers :— Messrs. A. B. Basset, H. Fortey, R. T. Glazebrook, 

 F.R.S., G. Heppel, J. J. Thomson, H. H. Turner, and Prof. 

 W. Thomson, Cape Colony. — The following papers were com- 

 municated : — The form of standing waves on the surface of 

 running water, by Lord Rayleigh, F.R.S. — A method of finding 

 the plane sections of a surface and some considerations as to its 

 extension to space of more than three dimensions, by Mr. W. L 



