PLATE XKS1— continued. 



FIGS. 



10 a — c. — Mesoyrapius multidens, var. eompactus, Lapworth. (Page 262.) 



10 a. Complete specimen, somewhat narrower than usual, reverse aspect. Dobb's Linn. 



Hartfell Shales (zone of Dicranog. Clingani). Lapwortli's Collection. 

 10 b. Shorter but broader specimen, showing virgular tube. Ibid. 



10 c. Specimen showing average width, reverse aspect. Ibid. 



11 a — e. — Mesoyrajitits modestus, Lapworth. (Page 263.) 



11 a. Typical specimen, showing characteristic appearance. Dobb's Linn. Lower Birkhill 



Shales (zone of Orthog. vesiculosus). Lapworth' s Collection. 

 1] b. Large, but incomplete, specimen. On same slab as fig. 11 a. 

 11 c. Specimen with long virgula, somewhat distorted. Ibid. Sedgwick Museum. 

 11 d. Narrower specimen. Ibid. On same slab as figs. 11a,, 11 b. 



11 e. Part of narrow specimen in partial relief. Fuehes-gau Farm, near Pont Erwyd. 



Lowest Llandovery (base of zone of Cephalog. acuminatus). O. T. Jones' Collection. 



12 a — d. — Mesograptus modestus, var. parvulus (H. Lapworth). (Page 264.) 



12 a. Type specimen, reverse aspect, but with surface removed, so as to show sicula. 



Figured, H. Lapworth, 'Quart. Journ. Geol. Soc.,' 1900, vol. lvi, p. 132, fig. 20 6. 



Gwastaden, Rhayader. Lower Gwastaden Series (zone of Cephalog. acuminatus). 



H. Lapwortli's Collection. 

 12 b. Larger specimen, well preserved, obverse aspect. Fuches-gau Farm, near Pont Erwyd. 



Lowest Llandovery Beds. O. T. Jones' Collection. 

 12 c. Small, broad specimen, reverse aspect. Ibid. 



12 tZ. Incomplete specimen, obverse aspect. Ibid. 



13 a — c. — Mesograptus modestus, var. diminutus, Elles and Wood, nov. (Page 265.) 



13 a. Typical specimen, reverse aspect. Skelgill, Ambleside. Skelgill Beds (Dimorpho- 



graptus band). Sedgwick Museum. 

 13 b. Complete specimen, bi-profile view. Dobb's Linn. Lower Birkhill Shales. Elles' 

 Collection. 



13 c. Complete specimen, bi-sealariform view r . Dobb's Linn. Lower Birkhill Shales 



(JDimorphograptus band). Lapwortli's Collection. 

 1-4 a — c. — Mesograptus magrius, H. Lapworth. (Page 266.) 



14 a. Type specimen, part in relief, part as an impression. Figured, H. Lapworth, ' Quart. 



Journ. Geol. Soc.,' 1900, vol. lvi, p. 133, fig. 21 b. Ddol Farm, Rhayader. 

 Gw r astaden Series (zone of Monog. fimbriatus). HL Lapwortli's Collection. 

 14 b. Smaller specimen in low relief. Rheidol Gorge, below Pont Erwyd, Cardiganshire. 

 Llandovery Beds. O. T. Jones' Collection. 



14 c. Narrow specimen, probably referable to this species. Ibid. 



15 a — d. — Amplexograptus perexcavatus, Lapworth. (Page 267.) 



15 a. Typical, complete specimen, obverse aspect. Kirkmichael Burn, S. Scotland. Upper 



Glenkiln Shales. Lapwortli's Collection. 

 15 b. Long specimen, obverse aspect. On same slab as fig. 15 a. 

 15 c. Complete specimen, intermediate view. Dobb's Linn. Upper Glenkiln Shales. 



Geological Survey of Scotland. 



15 </. Complete specimen in partial relief, bi-profile view. Ibid. Lapwortli's Collection. 



16 a — d. — Amplexograptus arctus, Elles and Wood, sp. nov. (Page 271.) 



16 a. Large, fairly complete specimen, long virgella. Spittal Railway Cutting, S. Wales. 



Lower Dicranograptus Shales. Geological Survey of England and Wales. 

 16 b. Complete specimen, showing characteristic form. Ibid. 

 16 c. Distal fragment, showing virgula. On same slab as fig. 16b. 



16 d. Specimen showing general form. Ibid. 



17 a — c. — Amplexograptus c&latiis (Lapworth). (Page 270.) 



17 a. Type specimen, sub-scalariform view. Figured, Lapworth, ' Quart. Journ. Geol. Soc.,' 



1875, vol. xxxi, pi. xxxv, fig. 8 c. Abereiddy Bay, S. Wales. Llandeil > Beds (zone 

 of Didymog. Murchisoni). Sedgwick Museum. 

 17 b. Incomplete specimen, sub-scalariform view. Ibid., fig. 8 b. 



17 c. Distorted specimen, bi-profile view, showing Diplograptus appearance. Ibid., fig. 8 a. 



18 a — e. — Amplexograptus confertus (Lapworth). (Page 269.) 



18 a. Specimen much distorted and compressed. Figured, Lapworth, ' Quart. Journ. Geol. 



Soc.,' 1875, vol. xxxi, pi. xxxiv, fig. 2 a. Porth Hayog, Ramsey Island. Upper 



Arenig (zone of Didymog. bifidus). Sedgwick Museum. 

 18 b. Specimen elongated by compression. Ibid., fig. 2 c. 

 18 c. Typical specimen, preserved as an impression, obverse aspect. Upper Arenig (zone of 



Didymog. bifidus). Geological Survey of England and Wales. 

 18 d. Two small specimens in association. Near Ffairfach Railway Station, Llandeilo. 



Upper Arenig (zone of Didymog. bifidus). Geological Survey of England and Wales. 

 18 e. Specimen of unusual length, preserved as an impression. Roadside E. of Church, 



Lampeter Velfrey. Upper Arenig Turubull's Collection, Sedgwick Museum. 



