PLATE XX. 



Genus Dicellograptus, Hopkinson. 



FIGS. 



1 a — d. — Dicellograptus complanatus, Lapworth. (Page 139.) 



1 a. Typical form. Dobb's Linn, Moffat. Upper Hartfell Shales (base of " Barren 



Mudstones"). Lapworth's Collection. 

 1 b. Typical form, showing " initial " and " lateral " spines. Same slab as 1 a. 

 1 c. More convergent form. Dobb's Linn, Moffat. Upper Hartfell Shales. Wood's 



Collection. 



1 d. Form with slightly curved stipes. On same slab as figs. 1 a and 1 }>. 



2 a — c. — Dicellograptus complanatus, var. ornatus, Elles and Wood, nov. (Page 140.) 



2 a. Typical specimen, showing apex of sicula. Dobb's Linn, Moffat. Upper Hartfell 



Shales (zone of D. anceps). Sedgwick Museum. 

 2 b. Specimen with extremely inconspicuous "lateral" spines. Dobb's Linn, Moffat. 

 Upper Hartfell Shales. Elles' Collection. 



2 c. Small specimen with more divergent stipes. Dobb's Linn, Moffat. Upper Hartfell 



Shales. Elles' Collection. 



3 a — e. — Dicellograptus anceps, Nicholson. (Page 141.) 



3 a. Typical form in low relief. Dobb's Linn, Moffat. Upper Hartfell Shales (zone of 



D. anceps). Wood's Collection. 

 3 b. Smaller specimen, showing apex of sicula. Ibid. Lapworth's Collection. 

 3 c. Very long specimen, but indifferently preserved. Ibid. 

 3 (/. Broad specimen, somewhat distorted, with indications of a " web " in the axil. Ettriek- 



bridge-end. Upper Hartfell Shales. Geological Survey of Scotland, Edinburgh 



Museum. 



3 e. Small, but well-preserved specimen in low relief showing mesial spines. Dobb's Linn, 



Moffat, Upper Hartfell Shales. Wood's Collection! 



4 a—f. — Dicellograptus intortus, Lapworth. (Page 14G.) 



4 a. Typical form. Birnock Water, S. Scotland. Glenkiln Shales. Lapworth's Collection. 



4 b. Somewhat narrow specimen with stipes crossing. Carco, Crawick Water. Glenkiln 

 Shales. Geological Survey of Scotland, Edinburgh Museum. 



4 c. Large, but incomplete specimen. Gwernyfed, Builth Boad, Eadnorshire. " Cieno- 

 graj^tus" Beds, Glenkiln. Dr. Fraser's Collection, Wolverhampton. 



4 (/. Specimen showing crossing of stipes near proximal extremity. Ibid. 



4 e. Specimen showing parallelism of stipes near proximal extremity. Ibid. 

 4/. Specimen showing proximal extremity. Same slab as fig. 4 d. 



5 a, b. — Dicellograptus, cf. divaricates, Hall. (Page 143.) 



•"> a. Wide form showing sudden increase in breadth of stipes. Wanloek Head, S. Scotland. 

 Glenkiln Shales. Lapworth's Collection. 



5 /'. Very poorly preserved specimen. Figured as D. '/»o^<7ic».s/.s\ Hopkinson and Lapworth, 



Quart, Journ. Geol. Soc, 1875, vol. xxxi, pi. xxxv, fig. 5 b. Abereiildv Bay, S. 

 Wales. Middle Llandeilo (Hicks). Sedgwick Museum. 



6 a — e. — Dicellograptus divaricatus, var. rigidus, Lapworth. (Page 144.) 



a. Typical form without " web " in axil. Birnock Water, S. Scotland. Glenkiln Shales. 

 Lapworth's Collection. 



6 b. Typical form with " web " in axil. Ibid. 



G c. Two narrower specimens in association, probably referable to this variety. Dobb's 



Linn, Moffat, Lower Hartfell Shales. Sedgwick Museum. 

 6 d. Specimen similar to fig. 6 b. 



6 e. Specimen similar to fig. 6 a. 



7 a — e. — Dicellograptus divaricatus, var. salopiensis, Elles and Wood. (Page 145). 



7 a. Typical form. Spy Burn, Shropshire. Rorrington Flags (" Ccen,ograptus' n Beds). 



Professor T. McK. Hughes' Collection, Sedgwick Museum. 



7 b. Ibid. 



7 c. Specimen with somewhat more widely divergent stipes. Birnock Water, S. Scotland. 

 Glenkiln Shales. Lapworth's Collection. 



7 d. Specimen showing sicula and " lateral " spines. Meggat Water, S. Scotland. Glen- 

 kiln Shales. Lapworth's Collection. 



7 e. Typical specimen. Birnock Water. Glenkiln Shales. Lapworth's Collection. 



