CLASS V. POLYPI: ORDER 2. ASTEROIDA. 639 



circles, and tinged with a variety of bright lively colors, very nearly represent the beautiful petals 

 of some of the most elegantly fringed and radiated flowers, such as the carnation, marygold, and 

 anemone. They are of various sizes, from that of the smallest thimble to the largest apple; and 

 have considerable power of locomotion, being able not only to move along upon the base, but 

 also in a reversed position upon their tentacles. Forbes describes one that walked up the sides 

 of a glass by alternately adhering by its disc and base, in the manner of a leech. They are vora- 

 cious in their habits, feeding upon almost any kind of small animal that comes within their reach; 

 shrimps and small crabs, whelks, and even small fishes are the common victims of their rapacity. 

 They have wonderful tenacity of life ; Dr. Johnston says : "They may be kept without food for 

 upwards of a year; they may be immersed in water hot enough to blister the skin, or frozen in a 

 mass of ice and again thawed ; and they may be placed in the exhausted receiver of an air-pump, 

 without being deprived of life or disabled from resuming their usual functions when placed in a 

 favorable situation." The most serious mutilations appear to be equally subjects of perfect indif- 

 ference to them ; their tentacles may break off and new ones will soon spring up in their place; 

 the whole upper part of the body may be cut away, and after a time the base will produce a new 

 mouth, oral disc, and tentacles, and proceed with its vital functions as if nothing had happened to 

 disturb the even tenor of its existence. Nay, it is said that if the whole body be torn away, 

 leaving only a portion of the base, this fragment will gradually produce a new creature. Still 

 less does the upper portion, when amputated in this manner, lose any fraction of its vitality. On 

 the contrary, as soon as it has recovered from the shock naturally consequent upon such 

 unceremonious treatment, it resumes its former activity, stretching out its tentacles and capturing 

 its prey, apparently quite unconscious that it has no stomach to put it into — for at first all the 

 food taken in at the mouth passes out at the opposite end, "just as a man's head, being cut oft', 

 would let out at the neck the bit taken in at the mouth." Some species of Actiniae are eaten, 

 and are said to be highly relishing food. 



THE LUCERNARIDJE. 



These animals, of which there are many species, are of a gelatinous consistence, and generally 

 adhere by a narrow stalk to sea-weeds or other floating submarine bodies. The anterior widened 

 extremity forms an oral disc, which is either quadrangular or octangular in its form, the angles 

 being more or less produced into pedicles, which bear numerous short, knobbed tentacles. When 

 the disc is quadrangular, the pedicles are forked at some little distance from their base, so that 

 there are always eight tufts of tentacles* They feed upon any minute animals that may stray 

 into the neighborhood of their tentacles, which, when seeking for food, are stretched out to their 

 full extent ; but as soon as any unfortunate creature comes in contact with them, they seize it, 

 and fold it into the mouth immediately. 



ORDER 2. ASTEROIDA. 



The asteroid polypes are all compound animals, inhabiting a polypidom, which consists of a 

 fleshy external layer, supported upon a calcareous axis. The polypes which are imbedded in 

 this fleshy mass are furnished with eight flat tentacles, placed in a single circle round the mouth, 

 and not unfrequently toothed or fringed on their margins. They are divided into several families. 



THE TUBIPORID^. 

 Of the typical genus Tuhipora there is only a single known species, the Red Oroan-Coral, T. 

 musica, inhabiting the Indian Ocean. The polypidom of this has a deep crimson color, contrast- 

 ing strongly with the bright green of the living polypes. 



animals are under a line in breadth, the number exceeds five and a half millions. There are, consequentl.v, fire and 

 a half millions of mouths and stomachs to a single zoophyte, contributing together to the growth of the mass." 

 From age to age, from the earliest periods to which the study of fossils can carry the history of our planet to the 

 present time, countless millions of these humble zoophytes have been ceaselessly toiling, separating calcareous matter 

 from the waters of the ocean, and fixing it in a permanent and solid form ; and immense beds of calcareous rock, in 

 various parts of the world, bear witness to their unceasing activity, perhaps even more than the coral islands of the 

 recent seas. 



