SILURIAN FOSSILS IN THE HEART OF THE CHAIN. 
457 
of limestone, calcareous grit and flagstone, in which we detected a few corals. 
Further west and in the parallel of the Kraka Hills, which lay to the south of our 
route, the limestone, black and slaty on fracture and associated with black schists, 
was found, at a little hamlet called Katchu-kova, to contain various characteristic 
Silurian types, such as Pentamerus Vogulicus, probably the same variety which 
occurs at Crasnoi Glasnova (p. 364), Murchisonia, apparently the same species as 
on the Is and at Nijny Tagilsk, with ill-preserved Terebratulse, Turbo, Encri- 
nites, &c. 
Again, if any misgivings had arisen concerning our inferences derived from 
previous sections, that the whole or nearly the whole of this chain had once been 
formed of palaeozoic strata which had subsequently been altered by metamorphism 
and eruption, they were at once dispelled by the evidences which here presented 
themselves. To the west of the black Pentamerus limestone and schist, we met 
with stony masses of quartz rock (altered sandstone), in which we detected casts 
of Bellerophons and Encrinites, which gave to the strata very much the appearance 
of the shelly Caradoc sandstone of the British Isles ; whilst in a very short distance, 
this same purple and grey quartz rock passed into chloride, talcose and micaceous 
slates, having the primary aspect of some of the masses of the Gara-tash mountain 
(see PI. IV.). In a country devoid of quarries and with few abrupt ravines, we 
could not pretend to put these various strata into geometrical order. It was 
enough for our purpose to find, that standing as we here did in the very centre ot 
the South Ural, we were surrounded by Silurian fossils, and that the strata in 
which they were imbedded graduated on either side into crystalline and metamor- 
phic overlying masses. The rocks in which we had found these remains are, in 
fact, the less elevated and less altered portions only of deposits, which in their ex- 
tension to the north or north-north-east rise into the culminating peaks of Yaman- 
tau, Bakty, Iremel, and Taganai, &c. Nor could we cast our eyes to the south, 
over the rugged and lofty Kraka Hills extending to the south and by west, and 
consider how when prolonged they terminate in the plateau of Kanikolsk and 
Preobrajensk which we had previously traversed, without being impressed with 
the Iremel itself was composed of shattered quartz rock, in short another Taganai. In the Appendix is 
given a list of the heights of the South Ural and adjacent lands as prepared by M. J. Khanikoff, whose 
admeasurements of the south-western embranchments of the chain assign to several points a very consi- 
derable altitude : thus Jamautau or Yamantau is placed at 5400 English feet (or 325 feet higher than the 
Iremel ! which has hitherto been ranked as the highest point of the South Ural), \ urma 3116, Zilmerdak 
■U37, Tutcha 3G51, Kalu 2753, &c. 
