PLATE XXXV— continued. 

 Figs. 



7 a — d. — Dimorphograptus physophora (Nicholson). (Page 353.) 



7 a. Long specimen with disc. Dobb's Linn. Birkhill Shales. 



Lapworth's Collection. 

 7 b. Similar specimen, sub-scalariform view. Ibid. 

 7 c. Long and narrow specimen, showing sicula bat no disc. On 



same slab as 7 a. 



7 d. Three young specimens in juxtaposition, showing sicula and 



beginnings of disc. Dobb's Linn. Birkhill Shales (zone of 

 Orthog. vesiculosus) . Elles' Collection. 



8 a — d. — Dimorphograptus cfr. longissimus (Kurck). (Page 354.) 



8 a. Typical specimen. Keisley, E. Ridlaw. Stockdale Shales 



(Dimorphograptus zone). Marr's Collection. 

 8 b. Narrow specimen, obverse view. Dobb's Linn. Birkhill Shales 



(zone of Orthog. vesiculosus). Elles' Collection. 

 8 c. Broad specimen. Fruid Water, Tweedsmuir. Birkhill Shales. 



Geological Survey of Scotland, Edinburgh. 



8 d. Small specimen. Quarter mile E. of Tarn Hows. Stockdale 



Shales (zone of Dimorphog. confertus). Sedgwick Museum. 



9 a — d. — Dimorphograptus erectus, Elles and Wood, nov. (Page 355.) 



9 a. Typical specimen, with proximal vesicle. Dobb's Linn. Birkhill 



Shales (zone of Orthog. vesiculosus). Elles' Collection. 

 9 b. Smaller specimen. Ibid. 

 9 c. Incomplete specimen. On same slab as 9 b. Ibid. 



9 d. Complete specimen. Dobb's Linn. Birkhill Shales (zone of 



Orthog. vesiculosus). Elles' Collection. 



10 a — e. — Dimorphograptus extenuatus, Elles and Wood, nov. (Page 358.) 



10 a. Typical specimeD, somewhat distorted. Coalpit Bay, Dona- 



ghadee. Birkhill Shales. Belfast Natural History Museum. 

 10 b. Ibid. 

 10 c. Ibid. 

 10 d. Smaller specimen. Main Cliff, Dobb's Linn. Birkhill Shales 



(zone of Orthog. vesiculosus). Elles' Collection. 



10 e. Young specimen. Dobb's Linn. Birkhill Shales. Lapworth's 



Collection. 



11 a — c. — Dimorphograptus elongatus, Lap worth. (Page 357.) 



11 a. Type specimen, figured Lapworth, ' Geol. Mag.,' 1876, pi. xx, 



figs. 12 a, b. Dobb's Linn. Birkhill Shales. Lapworth's 



Collection. 

 11 b. Specimen on same slab as fig. 11a. 

 lit'. Smaller incomplete specimen. Dobb's Linn. Lower Birkhill 



Shales. Elles' Collection. 



