THE HORNWRACK. 523 
showing the Sea Mat in its full glory is to take a living specimen from 
the stone or she-l to which it is affixed, and watch it under the microscope 
while the creatures are still in full activity. In the illustration, Fig. A, is 
shown a portion of the common Sea Mat, sometimes called the Hornwrack, 
of its natural size; and Fig. B represents a few cells of the same species 
rather highly magnified. 
On the upper-right hand cell may be seen the funnel-shaped group of 
tentacles belonging to one of the animals, and in the centre is a curiously 
shaped cell, which is analogous to the birds’ heads which we have so lately 
examined, the place of the lower jaw being supplied by a kind of lid. 
