378 THE MICROSCOPE. 



times purple, with small mouths placed irregularly, having 

 polypes with eight tentacles ; the bone is black, horny, and 

 slightly striated on the large branches. When alive, the 

 colour is most beautiful, generally yellow with red spots, 

 and is of a tough nature ; but it varies much, both in 

 shape and colour, presenting some of the most delicate 

 and graceful forms that can be conceived. Its elegant 

 skeleton is generally seen decorating the houses of sea- 

 faring persons. Hay, referring to the fan-shape of some 

 marine objects, says, " That the motion of the water 

 descends to a good depth, I prove from those plants that 

 grow deepest in the sea, because they all generally grow 

 flat, in the manner of a fan, and not with branches on all 

 sides like trees ; which is so contrived by the providence 

 of nature, for that the edges of them do in that posture 

 with most ease cut the water flowing to and fro ; and 

 should the flat side be objected to the stream, it would 

 soon be turned edgewise by the force of it, because in that 

 site it doth least resist the motion of the water j whereas, 

 did the branches of these plants grow round, they would 

 be thrown backward and forward every tide. Nay, not 

 only the herbaceous and woody submarine plants, but also 

 the Lytliopliyta themselves affect this manner of growing, 

 as I have observed in various kinds of corals." 



In the British family there are also, G. verucosa, G. pla- 

 comus, G. anceps, G. lepadifera, G. umbraculum, G. nobilis, 

 fig. 195, No. 9, &c. 



IBIDEM, the Isis, sea-shrubs, are small, but numerously 

 scattered in a soft fleshy integument. Isis hippuris, u Horse- 

 tail," so called from its resemblance to the Equiseta, 

 is the type by which this family is illustrated ; it has a 

 jointed stony stem, which rises into many loose branches. 

 The stem or support of the animal consists of white, 

 cylindrical, stony channelled joints, connected together by 

 black, contracted, horny intermediate ones. The flesh is 

 whitish, plump, and full of minute vessels ; the surface of 

 it is full of the little mouths of the cells, which are dis- 

 posed in a quincunx order, covering the polypes with eight 

 claws. 



ACALEPH.E. In great variety of form and colour, 

 swimming freely about the waters of the ocean, are found 



