NATURAL HISTORY. 
fragments—crystalline, semi-vitreous, and earthy 
Felspar of a reddish brown colour—quartz—com- 
mon schorl, (occasionally this and the last are met 
with distributed in small contemporaneous veins, 
apparently crystalline,)—chlorite—brown manga- 
nese ochre in occasional cavities—calcareous spar 
—and Lime stone (occasionally with coralloid res 
mains.) All these are for the most part mixed 
promiscuously in the same stratum, occasionally 
particular substances predominate but seldom if ever 
to the total exclusion of all others—the quartzose: 
and porphyritic fragments are but slightly rounded 
—ain some cases not even perceptibly so—the cal- 
careous portions have usually the appearance of 
being worn by attrition, 
AMYGDALOIDAL TRAP. 
(The Toad Stone of some Authors.) 
This rock is met with both north and south of 
Exeter—on the south-west side we may trace it for 
4 or 5 miles in the direction of Ide, and of Dunchi- 
deock ; many points occur along this range in which 
masses of this rock are found interposed between the 
beds of red sand stone, and as these points nearly fol- 
