50 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [DeC. 7, 



laria*', Pecoptensf, Sfc. ; 7. Ferruginous sandstone, with a thick 

 dendrites weathered out on its surface, from the same place ; 8. 

 Sandstone, with fucoid (?) markings, from the same place. 



§ B. From the Carboniferous Rocks of Lower Albany. — 1. Black 

 shale (slickensided), with Stigmaria ; 2. Dark-grey granular quartz 

 rock, with pyrites, from near the shale. 



§ C. Crystalline Bocks. — 1. A variety of brownish steatite, fit 

 for carving, from the Transvaal ; 2. Massive prehnite, from Banli- 

 berg, Cradock. 



§ D. Crystalline RocTcs from the Diamond-hearing Localities of 

 the Orange and Vccal Valley.- — -1. Block of calcite, from the Orange- 

 river district ; 2. Specular iron-ore ; 3. Galena; 4. Block of crys- 

 tallized quartz and galena ; 5. Lydite, with pyrites ; 6. Tremo- 

 lite ; 7. Selenite ; 8. Amethyst, quartz, agate, and garnet, from 

 the gravel. 



Remarlcs. — With reference to A, No. 1, the direction of the pre- 

 valent currents of the Karoo formation might be learned from a 

 study of these rippled surfaces. No. 2. Excavating the shales to 

 examine if they would yield roofing-material, the author found these 

 little bivalves [which are Estherice, of a new species — T. E.. J.]. 

 They were found at one spot only. No. 3. These are water-worn, 

 and furnish evidence, the author thinks, of great aqueous denudation. 

 Their matrix is often, if not generallj'', permeated by igneous rock. 

 [These and other specimens have the appearance of bones imbedded 

 in volcanic ash. — T. R. J.] 



Of the country formed of the Karoo strata Dr. Grey observes : — 

 The sweet-grass country, Dutch " Zout-Yeldt," yielding the valu- 

 able Karoo plant (Adenachcera parviflora) accompanies the Dicy- 

 nodon- (Karoo) beds of the great plateau, beginning on the eastern 

 side from about Queenstown, where the pasturage is of a mixed cha- 

 racter, locally " Gebrokenveld." From that district it is traceable 

 as in Bain's map, with its margin and watershed on the Zuur- 

 berg &c. The author is inclined to think that the bones of the 

 Dicynodons were deposited in the shallow waters of an inland sea — 

 the salts of soda that predominate largely in the salines of the soils of 

 the great Karoo plains, and help to form the "back-grond" of 

 of that region (sandy soil impregnated with common salt and car- 

 bonate of sodat, and some salts of magnesia and alumina), sup- 

 porting him, he thinks, in this vieAV §. 



* [The cast of a portion of decorticated stem, in hard blue shale. — T. R. J.] 



t [In a dark shale. Mr. Carruthers regards this Pecopteris as being pro- 

 •'iDablyP. Cistii (Br ongn\a,rt). Alethopteris Lonchitidis, Stbg., and Asterophyllites 

 equisetiformis, Brg. also accompany the foregoing. — T. R. J.] 



X The ash of some native plant (" Ganna-bush ") growing on the plains is 

 used extensively by the Boers in making hard soap, and contains a large per- 

 centage of carbonate of soda. The impure cai-bonate (lixivium), fii-st mixed 

 with sheep's tallow, is deprived of its carbonic acid by a long process of boiling, 

 requiring two or three weeks to be properly effected.. 



§ [The presence of Estheria, which, as a genus, inhabits brackish water, is in- 

 imical to the idea of an open sea having formed the Cradock beds, though in- 

 land brackish lakes would not be inconsistent. A fragment of an Encrinite (in 

 the Society's Museum) in one of the brecciated liiiiestones of the Rhenosterberg 



