WATSON — NOTES ON MKTAI-LlFEUOUri SADDLKS. 
305 
ing, wliile sometimes they arc also sufFiciently numerous to repay the 
cost of removing the whole of the rock coiitainiug them, liut the 
ore-bearijig parts of the saddles extend in reality to two separate sets 
of beds, distinguished as the ildch and the tidnhcds,//' and g y' (hg. 
4), the latter being immediately under the former. Tlie mineral, h b' , 
is associated in the thin beds, tj g' , under nearly similar conditions to 
Lign. J. — Vertical secliou of the " beai'ins beds," shovvuig tUo mode in whicli the ore is 
deposited. 
those Avhich have been described above for the thick beds (//') ; the 
ore deposits in the foimer are generally worked by driving cross-cut 
levels from the troughs of the thick beds (see dotted line o o' in the 
lignograph). No true vein-stone accompanies the ore in the saddles, 
but crystallized calc-spar is not unfrequently plated with ore on the 
cheeks of the fissures, and spar also exists beneath the ore on the 
