MEDUSID#:, 157 
to the phenomena of their development. 3. That many other so-called 
Meduside may from analogy be regarded, as in like manner, medusi- 
form gonophores. 4. But that there may exist, nevertheless, a group 
of medusid forms, which may give rise, by true reproduction, to 
organisms directly resembling their parents, and therefore worthy of 
being placed in a separate order, under the name of Medusida. 
According to Gegenbaur, the following families would belong to this 
Fig. 52,—A®quorea violacea, natural size (Milne-Edwards), 
order :—Oceanide, Thaumantida, quoridee (Fig. 52), Eucopide, 
Trachynemide, Geryonide, 4ginide. 
In the second division, these included under the family Zucer- 
nariade, the body is more or less cup-shaped, and frequently 
about an inch in height, terminating proximally in a stalk of variable 
length, and furnished with a free umbrella, which differs from a necto- 
calyx, with which it is often confounded, by the absence of a veil, in 
its mode of development, and in the nature of its canal system, having 
never less than eight radiating canals, and in the nature of its marginal 
bodies. If we regard this second division as an order, we may 
arrange it under two principal sections. In the first, including the 
genera Peagia and Lucernaria, the primary result of the generative 
