L.M.B.C. HYDROID ZOOPHYTES. 143 



believed it to be a Gonothyrcea, which Hincks only thought 

 probable from the shape of the gonotheca. I have now 

 found one specimen with gonothecas bearing extra-caps alar 

 medusaaform sporosacs, the character distinguishing the 

 genus Gonothyrcea, thus placing the matter beyond doubt. 

 These specimens are all more the height of G. lovvni, but 

 the number and shape of the castellations round the rim 

 of the calycle do not accord with those of that commoner 

 form. 



Galycella pigmcm, Alder (PL IX, fig. 2). 



In this species, lately transferred from the genus Lafoea 

 to that of Galycella, as I found it to have an operculum 

 which the Lafoeas have not, I have now found gonothecae, 

 which are said to be unknown by Hincks. They many of 

 them bear extra-cap sular gonophores which resemble, as 

 does the whole colony, those of Galycella syringa in 

 miniature. 



Galycella syringa, Linn. (PL IX, figs. 3 and 4). 



Hincks speaks of a sheath covering, as I understand, 

 the calycle of old specimens of Galycella syringa, and 

 having a serrated border which stands above and around 

 the operculum. I have seen this (as in fig. 4), and also 

 in some cases several series of these castellations encircling 

 the calycle one below another at varying distances apart 

 (as in fig. 3). In some cases I have seen three such sets 

 of castellations. I think it possible that these are really 

 old, worn-out opercula, new ones having developed inside 

 them. Lengthening of the calycle by growth would carry 

 these up. The single sheath with a serrated border (fig. 4) 

 would be the first stage. 



Filellum serpens, Hassall (PL IX, fig. 5). 



Most of our specimens of this form have a chitinous 

 crust in which the creeping stem is immersed, (fig. 5). 

 Professor Sir Wyville Thomson speaks of this, but Hincks 



