cxlvi BRITISH GRAPTOLITES. 



Hall describes and figures three new species of Graptolites, namely Tetra- 

 graptus projectus, Goniograptus macer and Trigonograptus Wilkinsoni, and a 

 species of Monograptus which he does not name ; he re-describes Didymog. gracilis 

 and Dicliog.octonarius,and re-figures Br yograptus Victorias, and Leptograptus antiquus. 



He recognises four main divisions in the Lower Ordovician of Victoria : 

 (1) Lancefield Series, (2) Bendigo Series, (3) Castlemaine Series, and (4) Darri- 

 will Series. The Graptolites characteristic of each group are fully given. The 

 Upper Ordovician is represented in a few localities, but the Silurian contains only 

 one or two species of Graptolites. 



A special point dwelt upon in this paper is the apparent want of harmony 



between the Graptolite zones of Australia and of Europe. Thus, in addition to 



the occurrence of Bryograptus and Leptograptus in association, Hall considers that 



Loganograptus appears very high up in the series, and never in association with 



Phyllograptus typus, while Didymog. bifidus, which is characteristic of an Upper 



Arenig Fauna in Europe, here disappears before Phyllograptus typus. 



In 1900 Elles published a paper on the "Zones of the 

 1900 . 



' Wenlock Shales," demonstrating the systematic chronological 



S-j LLSSj 



"The Zonal Classifica- arrangement of the various species of Graptolites in the 

 tion of the Wenlock Wenlock Rocks of Britain. A few new species were described, 

 Shales of the "Welsh and many already well-known forms, all with special regard 

 Borderland," 'Quart. to t j ie structure of the proximal end. 



' Under the species Monograptus Flemingii Elles recognises 



four varieties, a, (5, y, and 3, which are valuable zonally, as 

 they are practically confined to certain definite horizons. The same is the case 

 with M. vomerinus, of which she recognises three varieties ; M. flexilis, M. 

 irfonensis, and M. testis var. inornatus, are new forms. A new species of 

 Cyrtograptus, C. symmetricus, is also described. 



The Wenlock Shales are worked out in (1) the Builth district, (2) the Long 

 Mountain, and (o) the Dee Valley. Elles finds that in the Builth district they 

 are capable of division into six zones characterised by species of Cyrtograptus, and 

 that the majority of these Wenlock zones are also to be found in the other areas. 

 The evidences adduced in this paper prove for the first time in Britain, that the 

 Wenlock Shales are as capable of Graptolitic zonal division as are the Birkhill 

 Shales, and that these British Wenlock zones run parallel to the Wenlock zones 

 already suggested by Tullberg for Scandinavia. 



1900. In the same year Wood worked out the Graptolitic fauna 



Wood, of the Lower Ludlow Shales, and proved that these were 



" The Lower Ludlow equally capable of division into Graptolite zones. 



(l ,,. ' ,, Range and Distribution. — In this paper the distribution 



' Quart. Journ. Geol. °^ ^ ne Ludlow Graptolites is first worked out in the typical 



Soc.,' vol. lvi. Ludlow District, and four zones are recognised. Similar zones 



