CX XVI 



BRITISH GRAPTOLITES. 



1895. 



Lake, 



" The Denbighshire 



Series of South 



Denbighshire," ' Quart. 



Journ. Geol. Soc.,' 



vol. li. 



1895. 



Pemer, 



' ' Etudes sur les Grapto- 



lites de Boheme," pt. 



ii ; " Mouographie des 



Graptolites de l'Etage 



D." 



During the same year Lake noted the existence of both a 

 Wenlock and Lower Ludlow Graptolitic fauna in the Den- 

 bighshire series of S. Denbighshire. 



The second part of Perner's work on the Bohemian 

 Graptolites, including the species found in Etage D, was pub- 

 lished in 1895. Several new species are described and 

 figured, but owing to the poor state of preservation and 

 fragmentary condition in which these are found in Bohemia, 

 any certain identification of them is a matter of difficulty. 

 The following are described and figured : 

 Dichograptus (?) leptotheca, n. sp. 

 Tetragraptus caduceus. 



Didymograptus. — (Group A) — D. bifidus, B. Murchisoni, I), denticulatus, 1). 

 oligotheca, D. indentus var. nanus, D. spinulosus, D. clavulus, D. Barrandei, 

 D. Lapworthi, I), bifidus var. incertus, U. vacillanoides. (Group B) — D. v-fractus. 

 (Group C) — D. pennatulus : D. linguatus, 1). lonchotheca, D. pennatulus var. 

 hamatus, D. retroflexus. 

 Dicellograptus anceps. 

 Cryptographs tricomis. 

 Climacograptus tectus. 

 Diplograptus prlstis, 2). 

 D. terres, D. insculptus, D 

 vulgatus. 



Dendrograptus constrictus. 



A table is given showing the range of each species. 



A useful list of works published on the Graptolites in general and an historical 

 account of the Graptolites in Bohemia, are prefixed to this second part of Perner's 

 work. 



An important paper bearing on " The Phylogeny of the 

 Graptolites" was published by Nicholson and Marr in 18U5. 

 The authors conclude (1) that " the character of the hydro- 

 thecse is the most important point to retain in view in 

 separating different families of the Graptoloidea " ; and (2) 

 that the next most important point as " indicating genetic relationship," is the 

 angle of divergence of the stipes; while the number of stipes, on which the 

 present classification of the Graptolites largely depends, is relatively insignificant. 

 In consonance with these conclusions, the authors take the eight known species 

 of Tetvagraptus, and group round each of them those species of Diehograptvs, 



euglyphus var. angustus, D. lobatus, D. lingulitheca, 

 rugosus var. Fritschi, 1). truncatus, D. foliaceus var. 



1895. 



Nicholson and Marr, 



" Phylogeny of the 



Graptolites," ' Geol. 



Mag.,' dec. 4, vol. ii. 



