SEA-MATS AJSTD SHELLY COEALLINES. 71 



of two or three cells abreast ; thus narrow ribbon-like 

 branches are formed, which now and then divide into 

 two, then these into two more, and so on. These 

 branches thus become fan-shaped, wliich, by being 

 slightly curved, become segments of funnels ; and the 

 peculiar elegance of this coralline consists in the mode 

 in which these branches are set on the stem, viz., in an 

 ascending spiral curve, so that the effect is that of sev- 

 eral imperfect funnels set one within another, but whicli 

 yet you perceive, by turning the whole gradually round, 

 to compose a single corkscrew band of successive fans. 

 This whole structure stands upright in its natural state, 

 like a little compact shrub growing from a root ; and 

 as a good many are commonly associated together, they 

 form a sort of mimic grove, fringing the sides of dark 

 rocky sea-pools. 



The species is called the Corkscrew Coralline, or 

 sometimes the Bird's-head Coralline, the latter name 

 being assigned to it for a reason which you will pres- 

 ently perceive. The appellation by which it is known 

 to naturalists is Bugula avimilaria. 



We drop our specimen into a very narrow cell, com- 

 posed of parallel walls of thin glass, a very minute flat- 

 tened tank, in fact, such as can be put on the stage of 

 the microscope. Here, bathed in its native seawater, 

 as clear as crystal, we shall see it opening and expand- 

 ing its numerous polypides with the utmost activity and 

 evident enjoyment. 



You gaze ; but you know not what you see. The 

 presence of many lines representing transparent vessels 

 of strange and dissimilar shapes, overlying each other ; 

 and the swaying to and fro of curious objects, which 

 sti-ike now and then forcibly across the field of view. 



