SCYPHOMEDUSAE 



Table VIII 



Showing measurements in mm. of twenty-six specimens of 



Atolla chuni, Vanhoeffen 



381 



* Lappets included. 



The CENTRAL DISC is relatively broad, exceeding half the diameter of the bell. Its 

 surface as a rule is smooth, but sometimes there is to be seen a more or less fine or 

 irregular network of larger or smaller polygonal meshes. The radial furrows on the 

 central disc are mostly very faint and feebly developed according to the verrilli type, 

 or the border of the central disc is plain as in bairdi. In a few specimens only, from 

 St. 391, the furrows are deeper and a Httle broader, resembHng more the wyvillei type. 



The HEIGHT OF THE BELL (Plate XIV, fig. 3) is very variable, very flat individuals being 

 found together with relatively high ones. Often the central lenticular disc resembles a 

 highly vaulted watch-glass. On the whole this species seems to be a little higher than 

 wyvillei, and the central disc more vaulted. 



The FED ALIA are all as long as broad or a little longer than broad (Figs. 7 (i,b), very 

 regular, more or less circular in outline, mostly ball-shaped, forming together a row of 

 regular large round beads, seldom flattening each other, and not so uniformly or so 

 strongly compressed as in the diff'erent forms of wyvillei. They are always smooth, 

 without furrows. 



