MARINE POLYZOA. 53 



thirds the length of the cell, velum very convex. Ovicell ? 



Avicularium 0. 



Hab. S. Patagonia, Darwin. 



Margin of frond divided by shallow notches into small rounded 

 lobes. The specific name is derived from the regularly oval form 

 of the aperture, which is filled in by a very convex transparent 

 velum. 



9. CARBASEA ELEGANS. PI. LIV. figs. 6, 7; & PI. LVI. fig. 3. 



Cells oblong. Aperture nearly as long as the cell, truncate or 

 square below. Surface behind smooth. Ovicell ? Avicula- 

 rium 0. 

 Hab. Tasmania. 



The cells in this species most nearly resemble those of Flustra 

 papyracea : they are however less linear and more rounded at 

 the top, and not so long in proportion to their width. The little 

 filling-ill of the aperture at bottom affords a distinctive character, 

 as does the absence of avicularia, were the generic difference be 

 tween the two overlooked. 



10. CARBASEA INDIVISA. PI. LVIII. figs. 3, 4. 



Frond semicircular, undivided, subplicated ; cells oblong, sur- 

 face behind granulated. Ovicells ? Avicularia 0. 



Hab. New Zealand, Hooker. 



3. DIACHORIS. 



Cells disjunct, each connected with six others by tubular pro- 

 cesses ; frond sometimes partially adnate and decumbent. 



Diachoris, Busk. Voy. of Rattlesn. 382. 



The mode of arrangement and interconnexion of the cells in 

 this genus is remarkable and highly interesting. It represents, 

 in fact, a dissected Flustra. The cells are disposed in linear 

 parallel series, and those of two contiguous series are alternate 

 with respect to each other. Each cell is connected with one at 

 either end in the same linear series by a rather wide, short tubu- 

 lar prolongation, and with two on each side in the contiguous 

 series by narrower tubes ; so that each cell, except in the mar- 

 ginal rows, is connected with six others. The species, though 

 stated to be loosely adnate, are also capable of rising into inde- 

 pendent erect fronds, like the other Flustradse, and in the other 

 form would be more correctly described as decumbent than ad- 

 nate, as they are very loosely connected to the foreign base upon 

 which they lie. 



