372 THE MICROSCOPE. 



When shrunk, they are almost entirely hid amongst the 

 radiating plates. The specimens I have seen have varied 

 in size from three-tenths to half an inch in height. They 

 are found pendent from large boulders of sandstone, just 

 at low-water mark ; sometimes they are dredged from the 

 middle of the bay (Torquay). Their colour varies con- 

 siderably ; I have seen the soft parts white, yellowish, 

 orange-brown, reddish, and of a fine apple-green. The 

 tentacles are usually paler. During expansion, the soft 

 parts rise above the level of the calcareous disc to about 

 twice its height. The tentacles are pushed forth very 

 slowly, but sometimes are as long as the whole height of 

 the body ; and are terminated by a rounded head. The 

 mouth has the appearance of an elongated slit in the 

 centre of the disc ; it is prominent, and the lips are marked 

 with transverse striae of a white colour. When a solid 

 body is brought into contact gently with the tentacles, 

 they adhere pretty strongly to it, just as the Actinia do ; 

 but when they are rudely touched, they contract very 

 quickly, and if the irritation be continued, the whole soft 

 parts sink within the calcareous cup." 



ASTEROIDS^. This order of Zoophytes is named Aste- 

 roida from the polypes presenting the form of a star on 

 the surface of the fleshy mass in which they reside. The 

 fleshy tough mass is supported by hard calcareous spicula ; 

 some have thick branching processes, performing the part 

 of the skeleton in the human frame. This central internal 

 support is usually denominated the axis. The fleshy mass, 

 or covering, is possessed of sensation, and ramified by 

 various tubes and canals for the sustenance and other 

 functions of life of the polypes. Included with this genera 

 are Gorgoniadce, Pennatulidce, Alcyonidce, Isidce, and 

 Tubiporidce. 



PENNATULAD^J. The family derives its name from penna, 

 a quill, which the animal much resembles ; a spiculum 

 from one is shown at No. 3, fig. 172. Naturalists call 

 them Sea-pens ; a simple and appropriate term. 



On many parts of the coast, when the fishermen haul in 

 their nets, and more especially if baited with mussels, 

 there are found attached to the bait a number of polypes, 

 which the boatmen call Cocks' -combs, but naturalists, 



