JEQUOREA ALBIDA. Ill 



marginal capsules, two for every large tentacle, between the tubes, in 

 each of which there are from three to four granules arranged in a 

 cluster in the centre ; the capsules are perfectly spherical (c, Fig. 162) ; 

 the walls of the tentacles taper very gradually from the circular tube, 

 the swelling has but little prominence, and the pigment cells at their 

 base are not numerous, scarcely coloring it ; the lasso cells are arranged 

 in small knobs, scattered, at some distance from one another, all over 

 the surface of the tentacles; the spur of the tentacles (s, Fig. 162) is 

 placed directly opposite 

 the large tentacle on the 

 other side of the circular 

 tube ; the walls of this spur 

 are thick, and its hollow 

 space appears like a small 

 elliptical opening when 

 seen from above ; the un- 

 developed tentacles are solid conical protuberances, from which the 

 cavity of the tentacle is little by little hollowed out ; the tentacles are 

 usually carried tightly twisted like a corkscrew ; when in motion, the 

 tentacles are fully expanded, then bent at right angles and drawn 

 inside the veil and slowly thrown out, the tentacles almost closing the 

 opening of the cavity of the bell, giving these Medusae the appearance 

 of having numerous long tentacles (Fig. 161) arising from a small cir- 

 cular tube, the chymiferous tubes and the tentacles in their prolonga- 

 tion making almost a complete sphere. Specimens from one to two 

 and a half inches in diameter were taken at Naushon during Sep- 

 tember. 



Buzzard's Bay, Naushon (A. Agassiz). 



Cat. No. 279, Naushon, Mass., Sept. 1861, A. Agassiz. Medusa. 



Fig. 162. Magnified view of part of the marginal tube, c, capsule ; s, spur of the tentacles, t. 



