90 EXPLANATION OF THE PLATES. 
Fic. 5.—a-d. MERISTA PLEBEIA, Sowerby, sp. 
Atrypa, Trans. Geol. Soc., 2nd ser., vol. v., pl. lvi., figs. 12, 13. 
Merista, Brit. Dev. Brach., p. 20. 
From Brit. Dev. Brach., pl. iii., figs. 2, 2a, 26, and 3; the latter figure, 
reproduced on our Plate (fig. 5d), has a portion of the shell removed, 
' showing the spiral coil. 
Mippte Drevonran.—Localities : ‘It occurs abundantly in the limestone 
near Plymouth, Torquay, Ogwell, Newton Abbot, and Ilfracombe.” 
Brit. Dev. Brach., p. 20. 
Fig. 6.—SPrriFERA DISJUNCTA, Sowerby. 
Trans. Geol. Soc., 2nd ser., vol. v., pl. lii., fig. 8; pl. liv., figs. 12, 13. 
S. calearata, extensa, gigantea, inornata ; ibid., pls. lii.,liv., andlv. S. Ver- 
neuilii, Murch. Bull. Soc. Géol. France, vol. xi., p. 252. 
From Brit. Sil. Brach., pl. v., fig. iv. A small but typical example; Middle 
Devonian, Woodborough Quarry, near Newton Abbot. 
Mippie and Uprer Devontan.—‘ This very important species has been 
described and figured under many denominations. It occurs in the Upper 
Devonian grits and slates of Croyde Bay ; near Barnstaple, Braunton, 
&e.; at South Petherton; Tintagel, &e.; in the Middle Devonian lime- 
stone, near Newton Abbot ; at Ilfracombe; Barton, &e., near Torquay.” 
Brit. Sil. Brach., pp. 25, 26. Its occurrence in the Carboniferous slate 
of Ireland, although recorded by so eminent an authority as Mr. Davidson, 
is not, I think, sufficiently established. 
Fic. 7,—a, 6. CyRTINA HETEROCLITA, Defrance, sp. 
Calceola, Dic. Se. Nat., vol. Ixxx., fig. 3. Spirifera, Pal. Foss., p. 72. 
Cyrtina, Brit. Dev. Brach., p. 48. 
From Brit. Dev. Brach., pl. ix., fig. 1, a and 0. 
Mippite Drvonian.—An important and characteristic fossil of the Middle 
Devonian limestone of England and the Continent. In Devonshire it 
occurs near Plymouth; Torquay ; Newton Abbot ; near Totnes ; and at 
Hagginton Hill, near Ilfracombe, North Devon. Brit. Dev. Brach., p. 49. 
Fic. 8.—Rerzia Ferira, Von Buch, sp. 
Terebratula, Mém. Soc. Géol. de France, vol. iii. Retzia, Sandberger Die. 
Brach. des Rheinischen, &e., p. 34. 
From Brit. Dev. Brach., pl. iv., fig. 8. 
Mippte Drvontan.—* Characteristic of the Middle Devonian limestone of 
England as wellas of the Continent. It occurs at Barton and Lummaton, 
near Torquay; near Newton Abbot, and Plymouth.” Brit. Dev. Brach., 
p. 21. : 
Fic. 9.—ATRYPA DESQUAMATA, Sowerby. 
Trans. Geol. Soc., 2nd ser., vol. v., pl. lvi., figs. 19, 20; and var. compressa, 
ibid., figs. 21, -22. 
From Brit. Dev. Brach., pl. x1., fig. 1. 
