Geol. Mag. 1908. 



Dec. V, Vol. V, PI. XVIII. 



Fig. i.^The Pan Valley, from the Hourquette d'Alans. 



Fig. 2. — Silurian Slates (S.s.) thrust over Hippurite Limestone (H.L.), 

 Maillet brook, Cirque de Troumouse. Fr.P.=foot of the frontier 

 ridge (PalEeozoics). The almost horizontal limestone in the fore- 

 ground is bared over a considerable area ; behind the figure rises 

 a low vertical cliff of the slates with 'augen' torn from the limestone 

 in the lower part (H.L.a.). 



