. Elementary text-book of zoology, tr. and ed. by Adam Sedgwick, with the assistance of F. G. Heathcote. 250 CCELE^TERATA. To these is usually added a funnel or umbrella-shaped hydrophyl- liuin (fig. 192). These groups of individuals may in some Diphyids become free, and assume a separate existence as Eudoxia (fig. 193). The gonophores contain numerous ova in the manubrium, which often projects as a cone from the aperture of the bell. In the larva the upper nectocalyx is the first formed. Fam. Hippopodidae. The swimming column has two rows of nectocalycc«, and is situate on an upper lateral br
. Elementary text-book of zoology, tr. and ed. by Adam Sedgwick, with the assistance of F. G. Heathcote. 250 CCELE^TERATA. To these is usually added a funnel or umbrella-shaped hydrophyl- liuin (fig. 192). These groups of individuals may in some Diphyids become free, and assume a separate existence as Eudoxia (fig. 193). The gonophores contain numerous ova in the manubrium, which often projects as a cone from the aperture of the bell. In the larva the upper nectocalyx is the first formed. Fam. Hippopodidae. The swimming column has two rows of nectocalycc«, and is situate on an upper lateral branch of the stem. The male and female gonophores are grouped in clusters and are situate at the base of the nutritive polyp. Gh'ba Hippopus Forsk., Mediterranean. Fam. Diphyidae. With two very large nectocalyces at the. upper end of the stem and opposite to each other. Dipliyrs acuininuta Lkt., dioecious; with J?i«7ii,ria camjHinuhitn. Aliyla 2>cntayona- Esch., with ciilmlilcs, Mediterranean. Sphceronecteg ~ = 3/on»j}7ii/rs Cls., Sj). f/racilis C'ls. with Di^To- •pliysa inermis. Mediterranean. (4) Sub-order: Discoidece. Stem compressed to a flat disc, with a system of canal-like spaces (i-eutral cavity). Above lies the pneumatocyst in the form of a disc-shaped reservoir of car- tilaginous consistence composed of concentric canals opening to the exterior. The polypoid and medusoid appendages are situate on the under side of the disc. In the centre is a large nutritive Polyp, around which are a number of smaller ones. To the base of these small Polyps are attached the gonophores. The dactylozooids are not far from the edge of the disc. The gonophores are set free as small Medusa; (Chry- somitra), which do not produce the generative-* material till long after FIG. 103.—Part of a Di- phy'd (after R. Leuck- art). D, Hydrophyl- lium ; GS, genital nectocalyx ; P, polyp with tentacles. The individual groups se- parate as Eudoxia. rancan. Fam. V
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