LECTURE XII. 209 



soft bark, in which, as in the rest of the tribe, are 

 disposed the numerous branchings of the animal 

 part. The most elegant species of Isis is an 

 Indian Coral, growing to the height of about a 

 foot, and of a white colour with the horny joints 

 black. This, however, is the appearance of the 

 Coral when dried, as it is usually seen in cabinets; 

 but when recent, it is entirely covered with a soft 

 whitish bark with numerous pores, from each of 

 which protrudes a polype-head with eight arms. 



Some of the Coral tribe have their animal part 

 more nearly approaching (so far as we can trust 

 to the observations hitherto made) to that of a 

 Medusa than to that of a Polype. Of this kind 

 are those very numerous Corals known by the 

 title of Madrepores, and which constitute the Lin- 

 naean genus Madrepora. Their forms are very 

 various, some being of a globular shape, others 

 flattened, and others branched in various directions. 

 They are generally marked with numerous star- 

 shaped cavities, divided into several rays, but 

 many are rather marked into various winding 

 stripes composed of separate plates or lamina; and 

 all, when recent, exhibit a gelatinous animal sub- 

 stance situated either on the star-shaped cavities 



LECT. II. P 



