HISTORY OF RESEARCH. 



I \ x xvii 



1875. 

 Tromelin et Lebesconte, 



" Essai d'un Catalogue 



Raisonne des Fossiles 



Siluriens," etc., ' Assoc. 



Franc, pour l'avance- 



meut des Sciences.' 



recorded. 



From the " Schistes ardoisiers " Tromelin and Lebesconte 

 record Didymograpsus Murchisoni, Gr. Hisingeri, and Gr. 

 Sedgwiclci. In the lowest part of the third fauna, namely the 

 zone of ampelites and phtanites of Anjou and Lower Loire, 

 they recognise Gr. colonus, Gr. Beclci, Gr. Nilssoni, Gr. spiralis, 

 and Diplo. folium, while from the upper zone or " ampelite 

 nodules " Gr. Bohemicus, Gr. Beclci, and Gr. priodon are 



1876. 

 Linnarsson, 



" On the Vertical 



Range of Graptolites 



in Sweden," ' Geol. 



Mag.,' dec, 2, 



vol. iii. 



In a valuable paper " On the Vertical Range of the 

 Graptolites in Sweden," Linnarsson showed that Graptolites 

 occur on at least six distinct horizons in the Cambrian and 

 Silurian rocks of Norway and Sweden each horizon being 

 marked by different forms, and he satisfactorily parallels them 

 with known horizons in Britain : (1) the Olenus Shales with 

 the Upper Dolgelly of North Wales; (2) the Dictyonema 

 Shales with the Dictyonema-bearing beds in Britain and the Baltic provinces; 

 (3) the Lower Graptolitic Shales with the Skiddaw and Quebec groups ; (4) the 

 Middle Graptolitic Shales with the Moffat series; (5) the Upper Graptolitic Shales 

 with the Coniston and Gala beds; (6) the Higher Silurian with the Wenlock and 

 Ludlow. 



A general review of Linnarsson's paper, by Nicholson, 

 accompanied it. In addition to discussing the various 

 British strata corresponding to Linnarsson's five Swedish 

 zones, Nicholson gives diagnoses and figures of four new 

 genera from the Skiddaw Slates, previously included by 

 him under the single genus Bichograptus. These are (//) 

 Trichograptus, type T.fragills; (l>) Temnograptus, T. multi- 

 plex ; (c) Schizograptus, 8. reticularis ; (</) Ctenograptus, 



1876. 

 Nicholson, 

 " Notes on the Corre- 

 lation of the Grapto- 

 litic Deposits of Sweden 

 with those of Britain," 

 ' Geol. Mag.,' dec. 2, 

 vol. iii. 



( '. annulatns. 



187(5. 



M'Coy, 



" On a new Victorian 



Graptolite," ' Ann. 



Mag. Nat, Hist.,' ser. 



4, vol. xviii. 



1876. 



Tijmquist, 

 " Nyblottad pro til nied 

 PhyJlograptus skiffer i 

 Dalarne," 'Geol. Foren. 

 i Stock. Forh.,' no. 30, 

 bd. 3, no. 8. 



A new species of Graptolite was described and figured by 

 M'Coy from the Bendigo beds of Victoria, under the name 

 Vidijmograpsus Thureaui, but he suggests that, if the genus 

 Didymograpsus is to be restricted to the two-branched forms, 

 this species should be made the type of a new genus — 

 Goniograptus. 



A short stratigraphical paper appeared this year by 

 Tornquist, on the Phyllograptus shales of Dalarne and their 



fossils. 



