Rev. T. Hincks on British Pohjzoa. 531 



swells out at intervals into ovate expansions from ■which the 

 cells originate, as in the genus u^tea. These give rise to 

 secondary cells, which bud from their' upper extremity *. 



Even in the genus ^tea we meet with one case, at least, 

 in which gemmation from a stolon is combined with gemmation 

 from the cell itself. In ^tea truncata the zoooecia are usually 

 developed on a creeping stem, which is sometimes divided by 

 joints into more or less fusiform internodes. But occasionally 

 a long and slender tubular offshoot rises from the back of the 

 primary cell, terminating above in a zoooecium ; from this 

 secondary zoooecium another tubular offshoot is in some cases 

 developed, bearing a third cell. Beyond this I have not seen 

 the process of gemmation carried. The tubular stem, pro- 

 ceeding from the dorsal surface of a cell and bearing another 

 cell at its extremity, must be regarded as a kind of pedicel f, 

 and we have therefore in JEtea truncata the direct develop- 

 ment of cell from cell, as w^ell as the production of zoooecia by 

 budding from a stolon. This seems to be the case amongst 

 the Crisiidm also, according to Ehlers. 



In the presence of these facts I cannot regard the Stoloni- 

 fera as a suborder. 



Suborder Ctenostomata, Busk. 



Group 1. HajLCTonellea^ Ehr. 



Zoarium fleshy ; zoooecia developed by budding from other 

 zoooecia. 



Group 2. Stolonifjeea, Ehlers. 



Zoarium horny or membranous ; zoooecia developed by 

 budding from the internodes of a distinct stolon or stem. 



The Stolonifera {=Vesiculariidre, Johnst.) range them- 

 selves under two divisions : in one the tentacles form a perfect 

 circle ; in the other, two of them are constantly bent outwards 

 and the circle is broken on one side. 



For the species in which this remarkable peculiarity was 

 first noticed t constituted the genus Gampylonema ; but 1 have 

 since ascertained that it has a wider range, and occurs, 

 amongst others, in the well-known Valkeria uva, Fleming. 

 It is met with only in species of the simplest structure, which 



• In some cases, however, the colony commences with a line of decum- 

 bent and adnate cells, assuming the habit of Jlippothoa, and from these 

 the erect shoots ri.se. I believe that these decumbent cells must be re- 

 garded as the morphological equivalent of the creeping stolon, and that 

 the more or less clavate swellings which occur on the latter, in both .^!tea 

 and Eucratea, are in fact aborted cells. 



t The primary cells, it may be noted, are sometimes pedicellate. 



36* 



