t>H YSOPHORID&. 1 5 5 



longest, and also with small cilia, each terminating in a globule, 

 which sometimes contains air; the interior tentacles are shorter, 

 simple, and fleshy. In the centre of these tentacula is the mouth, 

 in form of a small proboscis, leading to a simple stomach surrounded 

 by a somewhat glandular substance. The editors of the last edition 

 of the " Regne Animal " only mention one species, P. gigantea, a 

 native of the Mediterranean and other warm seas, of a beautiful 

 blue colour. Lamarck gives four species. De Blainville and others 



Fig. 51. Porpita pacifica (Lesson). 



consider, with Cuvier, that they are only varieties which Eschscholtz 

 reunites under one species. In Fig. 5 1 we have represented P. pacifica 

 (Lesson), the disc of which is twelve lines in diameter, without com- 

 prehending the tentacles. This disc is finely radiated on the under 

 surface with a brilliant argentine nacre. The membranous fold 

 which surrounds it is cut into, leaving light and perfectly straight 

 festoons. It is of a clear celestial blue colour, and very transparent. 

 The tentacles are much compressed, very thin and cylindrical, of a 

 light blue, and the glands are of an indigo blue colour. All the re- 

 productive individuals, which are placed in the lower part of the 

 body, are of a perfect hyaline white. 



