210 LECTURE XII. 



or on the winding laminated part of the surface, 

 according to the different species. The Madre- 

 pores are of a stony hardness, and this stony or 

 calcarious substance is perpetually secreted or de- 

 posited from the gelatinous animal part. The 

 genus Madrepora is not only very numerous but 

 very intricate ; many of the species being difficult 

 to describe, and their synonyms being often 

 confounded by different authors. The very large 

 globular Madrepores, covered with a winding or 

 running pattern in the manner of a labyrinth, are 

 commonly called Brainstones, and are often seen 

 of such a size as to measure nearly two feet in di- 

 ameter : others of similar shape are covered over 

 with numerous star-shaped spots or impressions. 

 Of the branched Madrepores one of the most re- 

 markable is that called the Cinnamon Coral or 

 Cinnamon Madrepore : it is often about a foot in 

 height, and of a pale brown colour, and when 

 recent, is said to diffuse a fragrant smell. The 

 muricated Madrepore is distinguished by its 

 remarkably roughened surface, rising into innu- 

 merable prominences, each perforated at the tip. 

 This species varies, perhaps more than any other 

 of the Coral tribe, exhibiting all the diversities 



