Sea-Anemone. 159 



the dig-estive eavit3^ Both the peristomial disc and the internal 

 surface of the digestive cavity are marked by fine radiating lines, 

 which are seen to correspond with the attachment to their under 

 and outer surfaces respectively of the vertical muscular lamellar 

 ' mesenteries/ which; radiating from a point in the centre of the 

 hydrorhiza to the outer wall of the body, as well as to the roof 

 of the perig"astric space, and to the outer surface of the tubular 

 stomach, divide the body cavity into a number of radiall^^-arrang-ed, 

 mutually inter-communicating, wedg-e-shaped compartments. Some 

 of these mesenteries fail by greater or less intervals to reach the 

 outer surface of the stomach, and they are called '^secondaiy^ or 

 ' tertiary* mesenteries, whilst those which attach themselves to that 

 organ as well as to the outer wall are called ^ primary/ The 

 greater part of the exteiiial warty integument having been re- 

 moved, the lines of attachment of the mesenteries to it are as 

 plainly seen as those similarly produced on the digestive and 

 peristomial surfaces. At the lower part of the Preparation one of 

 the mesenteries has been reflected back, and the decussating 

 muscular fibres which make up a large portion of its substance 

 are well seen. At a little distance internally to this mesentery, and 

 in connection with the free border of another similar lamella, where 

 it projects into the general cavity of the body below the level at 

 which the stomach opens into it, we see some of the generative 

 glands surmounted by certain long convoluted filamentous organs, 

 the so-called ' craspeda/ which are richly furnished with thread- 

 cells ; but which are often spoken of as renal organs, as concretions 

 in which guanin is said to exist have been found in connection 

 with them. The lower orifice of the digestive tube is seen to be 

 of about the same size as the oral inlet, but it is not seen in this 

 preparation to be guarded with a muscular sphincter as the mouth 

 is. In Actiniae there exists a demi-canal on each of the opposite 

 sides of the mouth, which is prolonged down the inner surface 

 of the stomach, and is continued a little way beyond the termi- 

 nation of the sub-cylindrical organ, so as to project as a free 

 languet into the general cavity of the body. The external surface 

 of the body is similarl}^ furrowed in this specimen, and an appeai'- 

 ance of bilateral symmetry is thus produced. The Actiniae and 

 Cerianthidae are the only Polypi s. Anthozoa in which the external 

 integument is not more or less indurated by inorganic deposit. 



