HISTORY OF RESEARCH. ci 



(Eichwald), and discussed the structure of this genus in considerable detail. He 

 shows that the polypary originates from a sicula, is basket-shaped, that the 

 branches bear cells along their whole length on their inner side, and that Dictyo- 

 nema " is therefore much more closely allied to the true Rhabdophora than is 

 usually supposed." 



One of the forms described by Kjernlf as Dictyonema norvegicnm is regarded as 

 a mutation of D. flabelliformis. The others are identical with it, while another 

 variety, var. conferta, had been recognised by Linnarsson (MS). Many other 

 species of Graptolites found in Norway are recorded, and their synonymies given, 

 but no descriptions or figures. 



He corrects previous views as to the age of the Bryograptus beds, and shows 

 that they occur in the upper part of the Dictyonema beds, in the passage beds 

 between Etagen 2 and 3. 



1882. A paper of decided importance was published by Tullberg 



Tullberg, m fafe year. Considerable differences of opinion had arisen 



rapoies ^ ag ^ o ^ e exac t, nature of the species figured and described 



'BihwK Vetenska ~>s m Hisinger's ' Lethea Suecica,' which was issued as far back 



Akad. Haudl.,' bd. 6, as 1837-40. It had become impossible to identify many of 



no. 13. his forms until they had been re-figured and re-described in 



the light of modern knowledge. This much-needed revision was undertaken by 



Tullberg in this paper. 



The paper commences with an excellent historical account of the work of the 

 older Swedish palaeontologists and of the part that each played in developing our 

 knowledge of the nature of Graptolites. Eight species of Graptolites are described 

 and figured, and in each case Hisinger's original type specimens are re-drawn and 

 re-described. The species include Clirnacograptus scalaris, Diplograptus pristis, 

 Diplog. teretiusculus, Monograptus Sagittarius, M. convolutus, Gephalogr aphis folium , 

 Didymog. geminus and Dictyonema flabelliforme. 



Four new species of Swedish Graptolites were described 



X, trc i- anc l figured in 1882 by Kurck from the M. cyphus beds at 



" N&gra nya G-raptolit- Bollerup, Scania. These were Monograptus revolutus, Diplog. 



arter Hn Skaue," longissimus, Geplialog. ovatoelongatus and Glimacog. undu- 



' Geol. Foren. Forh., latus, and two associated forms are compared with Dimorphog. 



Swanstoni and M. cyphus respectively. The figures are good 



and the structure well represented. 



1882. Some very interesting forms of Dichograptids from 



Herrmann, Christiania were described by Herrmann in 1882, which illus- 



Voriaunge Mittheil- trate well the powers of variation of one species as regards 



img iiber eine neue ., , „ .. , , T , ., , 



n x vx i.»,<-xT j. the number ot its branches. In a new species described 



Graptolitenart, ' ' Nyt _ l 



Mag. for Naturvid ' ^y nmi as Loganograptus Kjerulfi, he notes every gradation 

 bd. xxvii. from forms with five stipes to those with twelve and perhaps 



