Mr. Bain on the Geology of Southern Africa. 183 



species of Homalonotus* . They are remarkable TriloUtes with a hooked beak in 

 front ; hence I provisionally named them the " hawksbill." 



The next rock in superposition is a coarse red sandstone, of great thickness, 

 containing numerous imbedded quartz-pebbles, much resembling the older sand- 

 stones of the Cape, and, like them, containing no fossils, as far as my researches 

 go. It is this rock which forms the elevated ranges of the Cedar Berg, Swarte- 

 berg, and Cold Bokkeveld mountains, attaining in some parts an elevation of 

 6840 feet above the sea. Its contortions and flexures are such (see Section No. 5, 

 Plate XXI.) as to bid defiance to any calculation of its thickness. 



On the flanks of those mountains is an extensive deposit, principally of fissile 

 slates and sandstones, geologically higher, though locally lower, extending far into 

 the Karoo, and containing many fossils of a similar nature to those already 

 described. These beds are the last and uppermost of the Upper Silurian seriesf , 

 as developed in this country, and they disappear here under the zone of igneous 

 rocks marked blue in the Map and Section, and which everywhere divides the 

 palaeozoic from the later and more northerly strata. 



I have not yet discovered a vestige of limestone, marble, or corals in these 

 deposits. The Crinoids seem to have been plentiful enough, but are never found 

 in a perfect state. The finest I ever saw crumbled to pieces in my endeavours to 

 extract it from the rock, so that I can show no better specimens than a few 

 detached ossicles or joints. 



The further description of this line of Section, with its extensive Reptiliferous 

 strata, I shall leave (as stated at p. 176) until I have first described all the other 

 formations. 



Section No. 2. (Plate XXI.) — From near Cape Recife to Lower Zeekoe River. 



The fundamental rock of all the country stretching from Gamtoos River to the 

 Great Fish River, and bounded to the northward by the Bothus Hill and Zuurberg 

 Ranges, appears to be that of our 



Carboniferous Formation, 



which Hthologically differs but little from the quartzose sandstones of the Silurian (?) 

 ranges of the western parts of the colony (except that the carboniferous rocks have 

 no imbedded pebbles). This appearance led to a mistake on my part in the descrip- 

 tion given in my letter of April 1844 (see above, p. 54), where I classed them all as 



* The H. Herschelii, of Murchison. 



t It was to this fossiliferous palaeozoic series, here termed " Upper Silurian," that Prof.E. Forbes alluded 

 at the British Association Meeting in 1851 (Report of Sections, p. 58), when he called attention 

 to the discovery of "Devonian" rocks in Fezzan by Dr. Overweg, and in the Cape Region, as above 

 described. — Ed. 



VOL. VII. — SECOND SERIES. 2 C 



