EXPLANATION OF THE PLATES. 



PLATE XVIII — Plan of the Workings in the Drewit District, Jarrow Colliery, shewing the place of the 

 accident, the extent of the fire, after.damp, &c. 



PLATE XIX. 



Illustrates Mr. Wood's Account of Fossil Stems of Trees in Killingworth Colliery, &c , 



Article XXI. page 206. 



Fig. 1. — Shews the position of the Fossil in the Strata. 

 Fig. 2. — One of the Roots of Ditto. 

 Fig. 3.— Flattened portion of the Stem. 



PLATE XX. 



Map of the Newcastle Coal Field to illustrate Mr. Buddie's Synopsis of the several Seams 

 of Coal, &c., Article XXII. page 213. 



PLATES XXI. XXII. and XXIII. 



Illustrate Mr. Buddie's Paper on Sections of the Strata of the Newcastle Coal Field, Ar- 

 ticle XXIII. page 225. 



PLATE XXI,— Section, No. 1, from Jarrow to Holywell. 



Section, No. 2, from Redheugh to near Denton Hall. 

 PLATE XXII.— Section, No. 3, from Chirton to Walbottle. 

 PLATE XXIII — Section, No. 4, from South Shields to the Team. 



PLATES XXIV. and XXV. " 



Illustrate Mr. Witham's Description of a Fossil Tree, discovered in Cragleith Quarry, Ar- 

 ticle XXVII. page 294. 



PLATE XXIV. — Shews the position of the Tree in the Sandstone of the Quarry. 



^I^ATE XXV.— Fig. 1 — Represents a portion of a transverse slice from the Stem ; shewing the usual re<Tu- 



lar series of apertures, separated by medullary rays or insertions. The indications of 



concentric circles are not very decided. Found, 1830. 

 Fig. 2.— Represents a portion of the same slice, in which the regular structure is broken up 



by veins of calcarious Spar. 

 Figs. 3, i. — Representa portion of a transverse slice of the fragment, in which the medullary 



rays are very distinct. Found, 1331. 

 Fig. 5 — Represents, of the natural size, a transverse slice of a fragment of a supposed 



branch ; the central dark part is the pith. Indications of concentric rings are 



observable. 

 Fig. 6. — Represents the pith of the same slice, magnified in the same degree as all the 



figures, excepting 5. 

 Fig. 7 — Represents the junction of the pith with the first circle and medullary rays. 

 Fig. 8. — Represents two concentric layers, and a portion of a third. The dark part of the 



figure, at the upper part, being the pith. The junction of the layers exhibits the same 



appearances as in some of the recent conifera;. The medullary rays and hexagonal 



cells are precisely similar to those of the coniferas. 



