HYDROIDA.
Sertularia Rosea. Pl. I. fig. 6.
A species which has the cells in pairs on opposite sides of the central tube, with the openings turned outwards. In the more enlarged figure is seen a septum across the inner part of each cell which forms the base upon which the polype rests. Fig. 6 b indicates the natural size of the piece of branch represented; but it must be remembered that this is only a small portion of the bushy shrub.
Campanularia syringa. Pl. I. fig. 8.
This Zoophyte twines itself parasitically upon a species of Sertularia. The cells in this species are thrown out at irregular intervals upon flexible stems which are wrinkled in rings. They consist of lengthened, cylindrical, transparent vases.
Campanularia Volubilis. Pl. I. fig. 9.
A still more beautiful species, with lengthened foot-stalks ringed at each end. The polype is remarkable for the protrusion and contractile power of its lips. It has about twenty knobbed tentacula.