64 TF. Carruthers — On the British GraptoliteSy 



Rhynclionella lacunosa, Ammonites hiplex, A. tortisulcatus, and many 

 others, resembles the Carpathian Hmestone series. These Jurassic 

 beds form a vast table-land, extending probably from the northern 

 Dobnidscha mountains to the Chalk and Eocene hills near Shumla 

 and Varna; and are elsewhere overlain by the before-mentioned 

 Miocene and drift strata. 



The geological composition of the Dobrudscha mountains is much 

 complicated. Except a reddish-brown Lias marble of true Alpine 

 character, a well-marked Alpine Halobia shale, and a Triassic bed, 

 resembling the Muschelkalk of Mikultschitz in Silesia, and the cal- 

 careous Triassic strata at the Plattensee in Hungary, and containing 

 gigantic specimens of Spiriferina Mentzeli, numerous remains of 

 Terehratula vulgaris, etc., the older formations in the northern 

 Dobrudscha repeat exactly the Transylvanian series, but without 

 the rich coal measures of the Banatic countries. 



Igneous rocks, namely many granite-like masses, a quartziferous 

 porphyry, and a great melaphyre dyke, penetrate this older forma- 

 tion, as well as the Inferior and Middle Triassic strata. In addition 

 to this, I will further state that I am of opinion that the Gneiss and 

 Granite which the Danube touches near the town of Matschin, opposite 

 Galatz, are identical with that through which the river passes at the 

 perilous Iron-gate and in the high countries between Passau and 

 Krems. It will be seen, therefore, that the Dobrudscha mountains, 

 although not more than 1600 feet in altitude, embrace a rich series of 

 deposits representing many types of formations widely removed from 

 one another both in central and western Europe. 



ly. A Eevision of the Bkitish Graptolites, with Descriptions 



OF THE New Species, and Notes on their Affinities.^ 

 By Wm. Carruthers, F.L.S., F.G.S., Botanical Department, British Museum. 



(PLATE V.) 



IT is of the first importance in Natural History to adopt a precise, 

 and if possible a received terminology, and strictly to adhere 

 to it. From the very different opinions that have been entertained 

 regarding the nature of graptolites, a curiously mixed set of terms 

 have been employed in their description, some being suggested by 

 their supposed resemblance to plants, others being obtained from 

 their affinities to animals. Discarding these I shall employ the 

 terminology proposed by Allmann and Huxley for the Hydrozoa, 

 now generally adopted', asking the reader to take here for granted 

 what I hope presently to establish, that these fossils have their 

 nearest allies in this class, and consequently that the terminology is 



1 As the chief purpose of this paper is to describe the new species noticed in the 

 list I supplied to the recently puhhshed edition of "Siluria," along with others not 

 referred to there, and to give the reasons for the changes introduced, i; shall freely 

 use the communications I made to Sir Rod. I. Murchison, as well as two papers 

 printed by me in the "Intellectual Observer," vol. ix. p. 283 and 365. I may be 

 allowed to refer readers interested in these fossils to these papers and to the note in 

 " Siluria," for observations which are here summarized or entirely omitted. 



