152 



THE VOYAGE OF H.M.S. CHALLENGER. 



t T. Tentacula. Tentacles. Tentakeln. 



The corona of tentacles in the Medusae corresjwnds originally to that of the nearly 

 related Polyps, and is therefore placed on the margin of the umbrella in the Medusae, as 

 it is on the margin of the peristome in the Polyps ; in many Medusae, however, the ten- 

 tacles assume a secondary position, and are sometimes transferred to the dorsal, sometimes 

 to the ventral surface of the umbrella. 



The gelatinous concavo-convex disk, the most voluminous part of the Medusa, and in 

 most cases forming the principal part of the body ; the upper convex surface (exumbrella) 

 passes into the lower concave surface (subumbrella), at the margin of the umbrella. 



Adradiale Schirm-Pedale. 



Schirmkegel (Schirmkuppel). 



Schirm-Pedale. 



Elastische Fasern der Schirm-Gal- 



lerte. 

 Scliirm-Gallerte. 



Interradiale Scliirm-Pedale. 



Zungenkegel oder Gastralkegel. 



Schirnirand. 



Perradiale Schirm-Pedale. 



Magenstiel (gallertiger, solider Stiel). 



Schirmhoker. 



Peripherer Schirmkranz. 



V. Velum. 



Velum. 



Eandhaut. 



A muscular, thin, membranous ring, which, in the section of the Craspedota, projects 

 freely downwards and inwards from the umbrella margin, as a process of the subum- 



