| Mr. Busk, however, does not know of any gradations now existing between a zooid and an avicularium. |
| Vittae linear, extremely narrow, entirely lateral, and extending the whole length of the cell from the base of the avicularium. |
| It may be desirable to separate generically the species having the hemispherical apertures, median ciliated pore, and sublateral avicularium. |
| In this genus, in all those species in which the second avicularium occurs, each individual cell is provided with one. |
| It also wants the raised bands which in C. amphora pass from the sides of the mouth to the apex of the avicularium in front. |
