100 



and might, in this case, have been classed witfe 

 the lamellar, into which (on the large scale) it 

 occasionally passes. 



The beds are sometimes straight, at others- 

 curved, and they are often placed in many differ- 

 ent directions within a small space ; varying in 

 position from the horizontal to the vertical. 



They are also frequently jointed, or divided 

 at right, or oblique angles, into cuboidal or pris- 

 matic forms. In these cases they might equally 

 be referred to the large concretionary structure. 



The form of a bed, or pseudo-stratum, is often 

 assumed by the trap rocks, or the rocks of the 

 overlying division, in consequence of their being 

 deposited on a real stratum. 



That form also results from the intrusion of 

 veins between parallel strata, and the distinctions 

 are considered in treating of veins. It assumes the 

 appearance of true stratification in a very accurate 

 manner, when, by the wearing away of the upper 

 of the including strata, it occupies the surface. 



STRATA. Sometimes also called beds by 

 many geologists. 



