THK FUNGIA. 206 



tentacles differs in the various species, and is often 

 very considerable. 



When the polyps are removed from the stem, the 

 little hollows with their imperfect divisions become 

 visible all over the poly pier. The latter assumes the 

 most varied forms, according to the manner in which 

 the polyps are reproduced. Sometimes they are most 

 complex and elegant, as in the case of the Millejpora 

 oUcicornis (fig. 42). 



These animals differ from the astroides proper in 

 the arrangement of their polypi, and from the coral- 

 lines in the absence of the fleshy incrustation around 

 the polypier. The polypier is wholly calcareous. Its 

 development is owing to the hardening of the trans- 

 verse divisions of the polypi and of their external 

 covering. Their growth is irregular, and it leaves no 

 trace of the animals themselves except the irregular 

 pores. They are found in the seas of the North and 

 of America. 



The variety of entirely calcareous polypiers is very 

 numerous. One in particular we must not overlook — 

 the jungia, so called from its resemblance to the ve- 

 getable fungi. The animal of this sp^^cies is gelatinous 

 or membranous, somewhat oval in form, abd much flat- 

 tened. The engraving (fig. 43) represents a mouth in 

 the centre of a large disc, the interior of which is made 

 solid by a calcareous deposit, while the solid cure is 



