G. DYNAMENA. 77 



cells simple, of a long oval form, united in groups of 

 from three to six, but not coalescing with each other ; 

 ovaria of a pyramidical form ; height from one to two 

 centimetres. 

 Bay of Cadiz. 



FALCATED. 



22. Aglaopiienia falcata. Stem branching, and 

 flexuous ; cells tubular, bulging, and imbricated ; ova- 

 ria dispersed and oblong. 



European seas. 



DYNAMENA. 



Plant-like, cartilaginous, somewhat branching, 

 garnished through the whole extent with cells in pairs 

 and opposite. 



The Dynamenas are distinguished from the other 

 genera of their order by their minuteness, their sessile 

 and opposite cells, and their mode of ramification ; 

 characters which are not found in the other Polypi- 

 doms of this order. The cells are sometimes so 

 transparent, that they can only be perceived by a 

 strong magnifier, when they first leave the sea, and the 

 polypi are yet alive. One is then tempted to imagine 

 them naked polypi, fixed to their stem by a pedicle of 

 greater or less length ; but we soon recognise the cell 

 which serves for a retreat to the animalcula ; and in 

 the Polypidoms preserved in collections these are often 



