266 DESCRIPTIVE CATALOGUE. 
677. Metamorphosed argillaceous slate, with intercalations of basaltic rock. 
678. Altered argillaceous slate—colour, grayish black; joints and seams coated 
with carbonate of lime. : 
679. Greenstone (?)—a close-grained, compact rock ; slightly crystalline in struc- 
ture. 
680. Metamorphosed marly clay—colour, red; very compact; has a trappous 
appearance. 
