146 THE CRUISE OF THE BETSEY ; OR, 



they compose. Every polygonal star in the mass is the house 

 of a separate animal, that, when withdrawn into its cell, pre- 

 sents the appearance of a minute flower, somewhat like a 

 daisy stuck flat to the surface, and that, when stretched out, 

 resembles a small round tower, with a garland of leaves bound 

 round it atop for a cornice. The Astrea viridis, a coral of 

 the tropics, presents on a ground of velvety brown myriads 

 of deep green florets, that ever and anon start up from the 

 level in their tower-like shape, contract and expand their pe- 

 tals, and then, shrinking back into their cells, straightway be- 

 come florets again. The Lower Lias presented in one of its 

 opening scenes, in this part of the world, appearances of simi- 

 lar beauty widely spread. For miles together, we know 

 not how many, the bottom of a clear shallow sea was paved 

 with living Astrese : every irregular rock-like coral formed a 

 separate colony of polypora, that, when in motion, presented 

 the appearance of continuous masses of many -coloured life, 

 and when at rest, the places they occupied were more thickly 

 studded with the living florets than the richest and most 

 flowery piece of pasture the reader ever saw, with its violets 

 or its daisies. And mile beyond mile this scene of beauty 

 stretched on through the shallow depths of the Liasic sea. 

 The calcareous framework of most of the recent Astrese are 

 white ; but in the species referred to, the Astrea viridis, 

 it is of a dark-brown colour. It is not unworthy of remark, 

 in connection with these facts, that the Oolitic Astrea of 

 Helmsdale occurs as a white, or, when darkest, as a cream- 

 coloured petrifaction ; whereas the Liasic Astrea of Skye is 

 invariably of a deep earthy hue. The one was probably a 

 white, the other a dingy-coloured coral. 



The Liasic bed of Astrese existed long enough here to at- 

 tain a thickness of from two to three feet Mass rose over 

 mass, the living upon the dead, till at length, by a deposit 

 of mingled mud and sand, the eflect, mayhap, of some change 



