PLATE XXXIII. 



Genus Glossograptus and Sub-genus Hallograptus. 



Figs. 



1. — Glossograptus cfr. ciliatus, Emmons. (Page 309.) 



Small specimen (young). Ty Obry, near Portmadoc. Llandeilo. 

 Sedgwick Museum. 



2 a — j. — Glossograptus Hincksii (Hopkinson). (Page 309.) 



2 a. Typical specimen, bi-profile view, showing apertural spines. 

 Wanlock Head. Glenkiln Shales. Lap worth's Collection. 



2 b. Typical specimen, sub-scalariform view, showing septal and aper- 

 • tural spines and thread-like virgula. Ibid. 



2 c. Small specimen, scalariform view showing septal spines. On 

 same slab as 2 a. 



2 d. Specimen in sub-scalariform view, showing septal spines, septal 

 strand, and virgula. Ibid. 



2 e. Young form, showing numerous spines in the proximal region. 

 Hartfell (?). Hartfell Shales. Lapworth's Collection. 



2/. Long specimen, with robust apertural spines. Hartfell. Hartfell 

 Shales (zone of Glirnacog. Wilsoni). Sedgwick Museum. 



2 g. Fragment, showing septal and apertural spines. Hartfell. Hart- 

 fell Shales (zone of Glirnacog. Wilsoni). Lapworth's Collection. 



2 h. Narrow specimen, bi-profile view. Ibid. 



2 i. Short specimen, sub-scalariform view, showing septal and apertural 



spines and robust virgular tube. Birnock Water. Glenkiln 

 Shales. Lapworth's Collection. 

 2j/'. Similar specimen. Ibid. 



3 a — d. — Glossograptus Hincksii, var. fimbriatus (Hopkinson). (Page 312.) 



3 a. Typical specimen, figured Elles, ' Quart. Journ. Geol. Soc.,' 1898, 



vol. liv, p. 521, fig. 32. Ellergill. Skiddaw Slates (Ellergill 



Beds). Sedgwick Museum. 

 3 b. Somewhat distorted specimen. Rein Gill, Wandel Burn. Glenkiln 



Shales. Geological Survey of Scotland, Edinburgh. 

 3 c. Young form. Minnoch Water, opposite Glencaird Lodge, W. of 



Glen o'Trool. Glenkiln Shales. Ibid. 



3 d. Typical specimen, broad. Wandel Water. Ibid. 



4 a — c. — Glossograptus arauf/nis, Elles and Wood, nov. (Page 314.) 



4 a. Typical specimen showing robust apertural spines. Sruffaunduff, 



^ mile W. of summit of Bencraff, Connemara. Arenig. Muff 

 and Carruthers' Collection. 

 4b. Incomplete specimen, figured Hopkinson and Lapworth as Glossog. 

 ciliatus, ' Quart. Journ. Geol. Soc.,' 1875, vol. xxxi, pi. xxxiv, 

 figs. 7 a — c. Llanvirn Quarry, Pembrokeshire. Llanvirn Beds. 

 Sedgwick Museum. 



4 c. Small specimen, distorted by cleavage. Nant-yr-Orlof, near Arenig. 



Arenig (zone of Didymog. bifidus). Fearnsides' Collection. 



5 a — e. — Glossograptus armatus, Nicholson. (Page 312.) 



ha. Poorly preserved specimen, figured Nicholson, 'Ann. Mag. Nat. 

 Hist.' [4], vol. iv, pi. xi, fig. 8. Thornship Beck, near Shap. 

 Skiddaw Slates. British Museum (Natural History). 



5 b. Specimen in sub-scalariform view. Kirriereoch Burn, Minnoch 



Water. Glenkiln Shales. Geological Survey of Scotland, 

 Edinburgh. 



