THE VISUAL CAPSULES. 337 



seven) minuter tentacles without bulbs, between every 

 two of the larger sort. The latter vary much in 

 number and size, and are not at all symmetrical, either 

 in position or arrangement, some being twice as close 

 together as others. In the specimen before me, the 

 quadrants of the margin formed by the radiating 

 canals pi'esent respectively the following numbers of 

 primary tentacles : — 16, 10, 9, 14; =49. Some, too, 

 of these are small and apparently developing. 



Besides these organs, the margin is furnished with 

 others, which, by those who consider the pigment 

 masses to be eyes, are believed to be organs of hear- 

 ing, but which seem to me rather to be the true media 

 of vision. They consist of cells, usually more or less 

 globose, containing one or more spherical bodies of 

 high refracting power. Prof. Forbes has not noticed 

 them in his description of this species; they are, how- 

 ever, large and peculiar ; — first in shape, being semi- 

 elliptical swellings of the substance of the marginal 

 canal, and secondly in the number of their spherules, 

 which varies from about 35 to 50 in each capsule. 

 The spherules are arranged in a double crescentic 

 row, those which form the middle being generally 

 larger than those at the extremities. The capsules 

 are eight in number, two in each quadrant, nearly 

 equally distributed ; but not holding any fixed rela- 

 tion of position to the tentacles. 



G 2 



