94 



CONCRETIONS, NODULES, 



G 



Wall-case 41. 



Cardiganshire. 



'/' 



17. 



Concretion, exhibiting an imperfect crystalliz- 



ation, termed " cone-in-cone" 



cliff 



Lloyd. 



jfAb 



Presented by the Rev. Henry R t 



18. — Argillaceous ironstone, termed " curl" or " cone* 



Salop. 



f> 



Measures. — Priorslee. near Weill 



19. — Argillaceous ironstone (" carl" or " cone-in- 



f> 



m 



Measures. 



D 



20. — Argillaceous ironstone (" curl" or " cone-in- 

 cone"), from Coal Measures, containing about 10 percent, 

 of iron, and used for making Roman cement. — From the 

 Pennystone beds, Ironbridge, Coalbrook Dale, Salop. 



21, 22, 23, 24, 25, and 31.— Spherical concretions of 



Permian 



'O 



Majrnesian 



26, 27, 28, and 29. 



stone, from the Permian rocks. 



30. Concretions of Magnesian Limestone, decomposed 



Permian. 



31._See2L* 



32. Concretions, filled with quartz, embedded in trap 



\ 



Case 4) 



Lower 



Silurian rocks. — D 

 sh ire. 



Yspytty Evan, Merioneth 



33. Concretions in trappean ash; as above. — Tyn-y- 



bryn, north-west of Bala, Merionethshire. 



34. Nodule of granular crystalline quartz, locally termed 



« boulders," and occasionally occurring in the Coal seam at 



Alder wasley, Derbyshire. 



35 and 36— Geode, locally termed "potato-stone, hnea 

 with crystals of quartz, and containing acicular crystals o 



P 



I It 



9 



r 



* 







!■ 



•J 



r,i 



M- 



Present* 



cretiona 



i 



'4 Hi 



1H» 







of the 



»t 



ft 



■ 



* Nos. 22 to 31, from Durliam. Presented by W. King. 



\l 



% 



