PLATE XIII. 



AzygOgraptuS, Nicholson, and Phyllograptus, Hall. 



FIGS. 



1 a, h. — Azygograptus Lajnvorthi, Nicholson. 



1 a. Specimens in association showing the sicula. Hodgson-How Quarry, Portinscale. 

 Skiddaw Slates. Woodwardian Museum. 



1 h. Part of a slab, showing mode of occurrence. Ibid. 



2 a — e. — AzygograpUis HicJcsii (Hopkinson). 



2 a. Type specimen showing sicula. Figured by Hopkinson as Tetragraptus HicJcsii, 



Quart. Journ. Geol. Soc, 1875, vol. xxxi, pi. xxxiii, fig. 12 c. Whitesand Bay. 



Middle Arenig (Hicks). Woodwardian Museum. 

 2 b. Two branches crossed in Tttnigrwptus form. Ibid., fig. 12 a. 

 2 c. Accidental association of three stipes. Ibid., fig. 12 h. 

 2 d. Specimen showing proximal end, well preserved. Whitesand Bay. Middle Arenig 



(Hicks). Woodwardian Museum. 



2 e. Similar specimen. Ibid. 



3 a, h. — Azygograptiis suecicus, Moberg. 



3 a. Portion of one slab, showing the mode of occurrence of this species. Barf. Middle 



Skiddaw Slates. Woodwardian Museum. 



3 b. Part of another slab ; specimens preserved as casts. Barf. Middle Skiddaw Slates. 



Postlethwaite's Collection. 



4 a, b. — Azygograptus ccelebs, Lapworth. 



4 a. Specimen, indifferently preserved, but showing sicula. EUei-gill. Upper Skiddaw 



Slates. Woodwardian Museum. 



4 b. Isolated stipe, showing form of distal thecse. Figured, Lapworth, Ann. and Mag. 



Nat. Hist. (5), vol. V, pi. v, fig. 16 c. EUergill. Upper Skiddaw Slates. Wood- 

 wardian Museum. 



5 a, b. — Phyllograptus, cf. typus, Hall. 



5 a. Specimen showing characteristic form. Skiddaw Slates. Woodwardian Museum. 



5 b. Specimen distorted by cleavage. Thornship Beck. Middle Skiddaw Slates. British 



Museum (Natural History), S. Kensington. 



6 a — -f. — Phyllograptus Anna, Hall. 



6 a. Specimen indifferently preserved. Carlside Edge. Skiddaw Slates. Woodwardian 



Museum. 



6 b. Elongated specimen preserved as a cast. EUergill. Middle Skiddaw Slates. 

 Lapworth's Collection. 



6 c. Specimen presented as an impression, showing the virgula (?). Figured, Elles, Quart. 

 Journ. G-eol. Soc, vol. liv, p. 494, fig. 16. Eandal Crag. Skiddaw Slates. Wood- 

 wardian Musevun. 



6 d. Small broad specimen. Eandal Crag. Skiddaw Slates. Woodwardian Museum. 



6 e. Specimen preserved as a cast. Skiddaw Slates. Lapworth's Collection. 



6/. Very short but broad specimen, preserved as a cast. Bennane Head, Ballantrae. 

 Arenig. Lapworth's Collection. 



7 a — -/. — Phyllograptus angustifolius. Hall. 



7 a. Specimen showing typical form. EUergill. Middle Skiddaw Slates. British Museum 



(Natural History), S. Kensington. 

 7 b. Broader example. 13assenthwaite Sand-l»eds. Middle Skiddaw Slates. Woodwardian 



Museum. 

 7 c. Form associated with P. typus (fig. 5 a). Skiddaw Slates. Woodwardian Museum. 

 7 d. Narrow example, narrowest proximally. Barf. Skiddaw Slates. British Museum 



(Natural History), S. Kensington. 

 7 e. Specimen showing well the form of tlic thecse. Bassenthwaite Sand-beds. Skiddaw 



Slates. Woodwardian Museum. 

 7 /. Specimen fairly well preserved. Barf. Skiddaw Slates. Woodwardian Museum. 



8. — Phyllograpttis ilicifolius, var. grandis, EUcs. 



Type specimen. Figured, Elles, Quart. Journ. Geol. Soc, vol. liv, p. 493, fig. 15. North- 

 east of Sleet How, Keswick. Skiddaw Slates. Woodwardian Museum. 



