140 LECTURE X. 



\vork entitled Fauna Suecica, as well as in the 

 earlier editions of his Systema Naturae, seems in- 

 clined to ^dmit the existence of this animal, and 

 forms a genus for it under the name of Micro- 

 cosmus. 



The genus Medusa contains a very remark* 

 able set of marine animals, which are generally 

 characterized by their soft and almost gelatinous 

 substance, their rounded and somewhat flattened 

 shape, their semitransparency, and their numerous 

 arms or tentacula. The species of this genus are 

 extremely numerous, and often present an appear- 

 ance in the highest degree elegant and singular. 

 They are of various sizes, some measuring one or 

 two, or even three feet in diameter, while others 

 are of a size so diminutive as scarcely to equal half 

 an inch in diameter. One of the most remark- 

 able of the larger kinds is the Medusa Pulmo, 

 which is seen in many of the European seas, and 

 is most common about the coasts of Italy and Si- 

 cily. It measures from one to two feet in diame- 

 ter : the body is nearly hemispherical, concave be- 

 neath, notched into several very slight or shallow 

 divisions round the edge, and furnished beneath, 

 with a very large and curious apparatus, consisting 



