Correspondence — Mr. R. Lijclelxkcr. 237 



Coal-measures, and contain even feeble black seams' of coal. In 

 such cases the boundary is well indicated by the presence of the 

 characteristic flora and fauna of the Lower Eothliegende, Walclda 

 piniformis (Schl.), W. filiciformis (Schl.), Odontopteris ohtnsi'oba 

 (Naum.), Callipteris con/erta (Stbg.), Catamites gigas (Bgt.), and 

 other characteristic plant-forms, or by such chai-acteristic fish-remains 

 as Acanthodes gracilis (Eotn.), Xenacanihus Decheni (Beyr.), PalcBo- 

 idscus angnstus (Ag.) and others. 



4. On the Integral Character (Selbstandigkeit) of the Dyas as a 

 " Terrain '' or " System " (newer nomenclature of the International 

 Geological Commission). 



' " We are now pretty generally convinced from such evidence as 

 is described above that the strata of the Dyas (or Permian) mark 

 the close of the Paleeozoic series of formations, as was admitted, 

 in fact, by the celebrated Sir R. I. Murchison ; it remains however 

 still a question whether the Dyas or Permian shall maintain its 

 position as an independent system, or should be subordinated to the 

 Carboniferous, perhaps under the name of Post-Carboniferous (" Post- 

 carbon"). This was not definitely settled at the sittings of the 

 International Commission for Geological Nomenclature, etc., at 

 Bologna in 1883, and the question remains to be decided at the next 

 International Congress at Berlin. 



" For a satisfactory answer to the question it must be referred 

 primarily to the German geologists, since it is in the German area 

 that the greatest and most significant changes took place in the 

 Dyas period, especially in the construction of continental deposits 

 (Festlandbildungen) ; the views of the Russian, English, and North 

 American geologists have also to be considered, since in those 

 countries discovery has followed quickly upon discovery in the 

 region of the Dyas in most recent times. 



•' The richest fauna and flora of the Dyas is certainly to be seen 

 in the Royal Mineralogical Museum in Dresden, where perhaps 

 geological confreres will be convinced that even from a palseonto- 

 loglcal point of view our Dyas deserves the same recognition as an 

 independent Terrain or System, as the Devonian in comparison with 

 the Silurian, and that notwithstanding the fact that several species 

 pass upwards from the Silurian to the Devonian." A. Ibving. 



C O I^ I^IE S IPO IsriDIE D^O IE . 



Js'OTE ON SOME SIWALIK BONES ERRONEOUSLY REEERRED TO A 

 STRUTHIOID {BROMJEUS (?) SIVALEISSIS, LTD.). 



Sir, — In examining the collection of Mammalian remains in the 

 British Museum for the purpose of cataloguing, I have come across 

 certain specimens from the Siwalik Hills, which have convinced 

 me that the phalangeals described and figured in the " PalcBontologia 

 Indica" (Mem. Geol. Surv. India), ser. 10, vol. iii. pp. 145, 146, 

 pi. xiv. figs. 2, -4, 5, 6 (1884), as belonging to a Struthioid, and 

 named JDromaus (?) sivalensis, are not Avian at all, but belong to one 



