PLATE XXX. 



Sub-genera Orthograptus and Glyptograptus. 



Figs. 



1 a — c. — Orthograptus calcaratus, Lap worth. (Page 239.) 



1 a. Typical specimen. Dobb's Linn. Lower Hartfell Shales. Lap- 

 worth's Collection. 

 1 b. Narrow specimen, compressed. Ibid. 



1 c. Shorter and broader specimen. Ibid. 



2 a — d. — Orthograptus calcaratus, var. basilicus, Lapworth. (Page 243.) 



2 a. Typical specimen, obverse aspect. Hartfell Spa. Hartfell Shales. 



Lapworth's Collection. 

 2 b. Smaller complete specimen. Dobb's Linn. Hartfell Shales. 



Lapworth's Collection. 

 2 c. Complete specimen showing characteristic view. Hartfell Spa. 



Hartfell Shales (zone of Dicranog. Glingani). Lapworth's 



Collection. 



2 d. Smaller specimen. On same slab as 2 c. 



3 a — c. — Orthograptus calcaratus, var. acutus, Lapworth MS. (Page 242.) 



3 a. Typical specimen, obverse aspect. Birnock, Leadhills. Glenkiln 



Shales. Lapworth's Collection. 

 3 b. Characteristic specimen, somewhat distorted. Ibid. 



3 c. Smaller specimen. Deugh Water, Knockingarroch, Carsphairn. 



Glenkiln Shales. Geological Survey of Scotland, Edinburgh. 



4 a — c. — Orthograptus calcaratus, var. tenujicornis, Elles and AVood, nov. (Page 



243.) 



4 a. Small specimen. Morroch Bay, two miles south of Portpatrick. 



Lower Hartfell Shales. Geological Survey of Scotland. 

 4 b. Specimen showing long virgula. On same slab as 4 a. 



4 c. Typical specimen, complete. Ibid. 



5 a — d. — Orthograptus calcaratus, var. vulgatus, Lapworth MS. (Page 241.) 



5 a. Distal part of characteristic specimen. Hartfell Spa. Lower 



Hartfell Shales (zone of Glimacog. Wilsoui). Lapworth's 

 Collection. 



5 b. Proximal portion, reverse aspect. On same slab as fig. 5 a. 



5 c. Complete specimen, obverse aspect. Hartfell Spa. Lower Hart- 

 fell Shales (zone of Glimacog. Wilsoni). Wood's Collection. 



5 d. Typical specimen, obverse aspect. On same slab as PI. XXIX, 

 figs. 4 b and c. Elles' Collection. 



