1817.J GENUS ACTIxVIA. 153 



a melon, and was divided into twenty-two equal lobes, re- 

 sembling those of the pulp of an orange, plaited in a zigzag 

 manner, the extremities being closed, by the junction of 

 their borders, like a purse which shuts at both ends. When 

 the animal begins to dilate, one perceives, at its superior 

 part, a white coloured disc, wliich is composed of small air- 

 vessels, that serve to support the animal at the surface of the 

 water, and is always uppermost when it floats, the mouth 

 being situated in the lower extremity. This vesicular disc 

 is surrounded with tubercles, corresponding to each lobe or 

 division. The plaits of the divisions, and t\^ black points 

 of their extremities^ are furnished with small suckers, by 

 means whereof tlie animal has the faculty of adhering, 

 pretty strongly, to any body. The opening of the mouth 

 is central^ linear, suiTounded by small plaits, whence those 

 divisions have their origin which serve as the base of the 

 tentacula, which are short and tuberculated, simple and 

 very small near the centre, trilobated and multilobated to- 

 wards their extremities — these tentacula are disposed in 

 rays, alternately great and small. The most conspicuous 

 tuberculated lobes have a small linear depression at their 

 summit. I did not remark that the tentacula were fur- 

 nished with suckers or fasteners, which one observes on 

 those of several other species of Actinia. 



This species, in common with many others, can as- 

 sume different forms: sometimes it resembles a reversed 

 vase, the base being more or less expanded, and the other 

 extremity more or less contracted; it can also lengthen 

 itself until the zigzag plaits of the divisions disappear. 



On the 29th December we arrived at Barbadoes. i 

 took my Actinia ashore, in a glass vase, and, after having 

 given it a change of water, it remained contracted in a 



