SY INFERIOR ORGANISMS. 113 



ata, Lumbricus hirticauda, L. simplicissimus, Pla- 

 naria retusa, Srachiurus quadruples, andSpirogra- 

 phis Spallanzanii. Some of these were found off the 

 coast of Genoa in 1805. Scoresby and Eiville soon 

 recognized other phosphorescent species, which 

 they dredged from the ocean in their voyages. 

 Macartney made known, in 1810, the luminous 

 Medusa scintillans, M. lucida, and another curious 

 little being closely allied to Medusas, called Beroe 

 fulgens. Peron and Lesueur, in their voyage from 

 Europe to the Isle of France, discovered the Pyro- 

 soma Atlantica (fig. 12 : 1, the entire animal mag- 



Fig. 12. 



nified ; 2, the phosphorescent surface of the body, 

 magnified 300 diameters), one of the most curious 

 of animals. It belongs to the tribe of Tunicata; 

 each individual resembles a minute cylinder of 

 glowing phosphorus ; sometimes they are seen 

 adhering together in such prodigious numbers, 

 that the ocean appears as if covered with an enor- 



i 



