cxlii BRITISH GRAPTOLITES. 



Victoriae, Bvyog. Clarki, Leptog. antiquus, Didymog. Pritchardi (a form occasionally 

 possessing three branches), D. Taylori, Tetrag. decipiens, Dictyonema pulchellum, 

 and he re-describes and figures Glonog.flexilis, G. magnificus, G. rigidus var. tenellus, 

 Phyttograptus species and Dictyonema Macgillivrayi. 



According to Hall, Leptograptus and Bryograptus here occur together on the same 

 slabs, and he explains this unusual association by concluding that in Victoria 

 Bryograptus ranges up to the Ordovician. 



1898. 



Elles, In 1898 Elles published a revision of the Graptolite fauna 



" The Graptolite Fauna of the Skiddaw Slates of the Lake District, the forms found 



of the Skiddaw Slates," j n these rocks being re-described, and particular attention 



' Quart. Journ. Geol. i • • -, , -■ , ■■, £ , 



^ being paid to details ot structure. 



Soc.,' vol. liv. ° r 



The development of Bryograptus is worked out in B. Kjerulfi, B. cf. Gallavei, and 

 B. ramosus ; and a new variety, var. cumbrensis, is described. The following species 

 are described : Glonograptus fiexilis, G. cf. tenellus, Glonograptus sp. ; Loganograptus 

 Logani; Trichograptus fragilis ; Temnograptus multiplex; Trochograptus dijfusus ; 

 Schizograptus reticulatus, S. tardifurcatus, sp. no v. ; Pleurograptus vagans ; Ptero- 

 graptus sp.; Dichograptus octobrachiatus, D. separatus, sp. nov.; Tetragraptus guadri- 

 brachiatus, T. Headi, T. crucifer, T. Bigsbyi, T. serra, and two new species, T. pendens 

 and T. Postlethwaitii ; Phyllograptus ilicifolius var. grandis, nov., P. Anna, P.typus, 

 P. ang ii stlf alius ; Didymograptus gibberulus. The structure of this last species is 

 worked out in detail, and a somewhat anomalous point of structure is noticed, 

 namely, the apparent presence of a second connecting canal, uniting the second 

 theca of the primary stipe with the first theca of the secondary stipe. 



The following species of Didymograptus are re-described : D. nitidiis, D. 

 Nicholsoni, D. affinis, D. extensus, D. patulus, D. gracilis, D. fasciculatus, D. v- 

 fractus, var. volucer, D. indentus, var. nanus, D. bifidus. 



The genus Azygograptus is considered by Elles to belong to the Dichograptidae 

 (comp. Wiman) rather than to the Nemagraptidae, on account of the structure 

 of the proximal end being similar to that in the Dichograptidaa. A. Lapworthi, 

 A. ccelebs, A. suecicus, are re-described, together with Leptograptus sp. ; Dicellog. 

 moffatensis ; Diplog. dentatus, D. cf. teretlusculus, D. appendiculatus ; Climacog. 

 Scharenbergi ; Cryptograptus ? antennarius, C. Hophinsoni; Glossograptus fimbriatus, 

 G. cf. Hinclcsii, G. armatus ; Trigonograptus ensiformis, T. lanceolatus ; Thamno- 

 graptus Doveri. Some of the above-mentioned species are figured. 



The range and distribution of the various species of Graptolites are given ; the 

 Skiddaw Slates are divided into zones and compared with similar beds in South 

 Wales and Sweden, the sub-divisions of the Skiddaw Slates agreeing closely with 

 those given by Marr in 1894. 



As regards the phylogenetic relationships of the Skiddaw Slates Graptolites, 

 Elles agrees with Marr and Nicholson in the main, namely, that (1) the re- 



