ACTIN0Z0A. 187 



l] lar When growth takes place chiefly in a horizontal 



^ e direction, the so-called lamellar form of corallum 



^ e results. Here, the secondary corallites are united 



^ throughout their whole height, and disposed in a 



e ^ linear series, the entire mass presenting one con- 



tinuous theca. Sometimes it is possible to count 

 Xe( i l the number of corallites, but often their several 

 n(l " calices merge, as it were, into a single groove, 



* °f traversed, perhaps, by a columella running parallel 



a to its sides, towards which two opposite rows of 



>7 ^ j septa are seen to converge. 



Both the lamellar and coespitose forms of coral- 

 }I ft- lum are liable to become massive by the union of 



rich several rows or tufts of corallites throughout the 



ion whole or a portion of their height. An illustration 



of this is afforded by the large gyrate corallum of 

 Mceandrina, over the surface of whose spheroidal 

 the mass the calicine region of the combined corallites 



less winds in so complex a manner as at once to suggest 



hus that resemblance to the convolutions of the brain 



arte which its popular name of Brain-stone Coral has 



or, been devised to indicate. 



less Basal gemmation, among sclerodermic Corals, 



affords very different products, according as the 

 pe- coenosarc remains soft, or deposits a ccenenchyma; 



appears under the form of stolons, or of stouter 

 > in connecting stems ; or even spreads out in several 



t of directions as a continuous horizontal expansion. 



:e d, -h this case it is evident that the latest formed 



a Parts of the mass are those which are situated 



ies, nearest to its circumference. 



al- 



widely 



the ^ted from one another, or closely aggregated 



0i and, perhaps, confused by reason of the scanty 



development of an intervening ccenenchyma. 



