ASTEROIDA. 211 



more highly magnified. It is much infested with parasites ; a vorti- 

 cella grows on it, and a sort of vibrio ; the latter in immense numbers, 

 forming aggregated clusters here and there ; the individuals adhering 

 to each other, and projecting in bristling points in every direction. 

 These animalcules vary in length ; some being as long as -fa inch, with 

 a diameter of yoVo" i nc h. They are straight, equal in thickness 

 throughout, and marked with distinct transverse lines ; they bend them- 

 selves about with considerable activity, and frequently adhere to the 

 polyp by one extremity, while the remainder projects freely." 



Some of this family attain a considerable size ; the Gorymorpha 

 nuians, one of the most beautiful of the group, attains a length of four 

 inches and a half. Of the beauty of its appearance, Forbes, who dis- 

 covered it in the British seas, speaks in the following terms ; " When 

 placed in a vessel of sea-water, it presented the appearance of a 

 beautiful flower. Its head gracefully nodded (whence the appro- 

 priate specific appellation given it by Sars), bending the upper part 

 of its stem. It waved it long tentacula to and fro at pleasure, but 

 seemed to have no power of contracting them. It could not be re- 

 garded as by any means an apathetic animal, and its beauty excited 

 the admiration of all who saw it." The general colour of, the creature 

 is a delicate pink, with longitudinal lines of brownish or red dots. 

 The tentacles are very numerous and long, and of a white colour ; and 

 the ovaries, which are situated immediately above the circle of tentacles, 

 are orange. Most of the Tubularidce inhabit the sea ; but one species, 

 the Cordyloplwra lacustris, is found in the dock of the Grand Canal, 

 Dublin, in water which is perfectly fresh. 



ASTEROIDA. 



The next, or second order of Zoophytes is named Ast&roida from 

 the polyps presenting the form of a star on the surface of the fleshy 

 mass in which they reside. (In title-page various species are dis- 

 tributed over the rock-work at the base.) Their organisation is supe- 

 rior to those previously described ; and there exists this difference, 

 that instead of the animals domiciling in a hard cell, they exist in a fleshy 

 tough crust, which is supported by hard calcareous spicula, and others 

 with 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 func- 

 tions of life of the polyp. This order contains three families, the Gor- 

 goniadce, Pennatulidce, and the Alcyonidce. 



