PROROCENTRUM. 87 



to form the luminous appearance which is so fre- 

 quently observed in the ocean. How marvellous 

 that these little atoms, which require a magnify- 

 ing power of 300, to be discerned, should produce 

 this extraordinary light ! The lorica of the only 

 species, P. micans, is pointed at the extremity, 

 oval in shape, and compressed. The creature 

 has no eye, but a proboscis, and cells can be seen 

 in the interior of the body. It is of a yellowish 

 waxy colour, similar to all the luminous Infusoria. 

 Layenella eucldora has a lorica shaped like a 

 bottle with a neck, and is of a beautiful green 

 colour, but quite clear, and having a bright red 

 eye. It is found in fresh water, with Conferva. 

 Cryptoglena conica has a shield-like lorica, which 

 folds inwardly at the sides, two proboscides, and 



