zoopnY'l'ES. 381 



Avhence four vessels diverge to opposite points of the 

 margin. These form elevated rihs, the surface being 

 gradually depressed from each to the centre of the in- 

 terspace. Externally, the centre of the disk is produced 

 into a fleshy peduncle, having a narrow neck, and then 

 expanding into a sort of secondary disk, of a square 

 form, with the angles rounded. This organ, which is 

 capable of varied, precise, and energetic motions, cor- 

 responds to tlie peduncle of a true Medusa, the angles 

 being the lips. These lips, which correspond in their 

 direction to the four internal ridges, are very protrusile, 

 and when the little animal is active are continually be 

 ing thrust out in various directions, sometimes everted, 

 but more commonly made to approach each other in 

 different degrees ; sometimes one being bent-in towards 

 the centre, sometimes all closing-up around a hollow 

 interior. These four lobes, thus perpetually in motion, 

 and changing within certain limits their form and their 

 relation to each other, remind one of the lips or the 

 tongues of more highly organized animals. The sub- 

 stance of this peduncle a})pears to be delicate!}' granu- 

 lar : but there is a verv manifest tendencv to a fibrous 

 character in its texture, the fibres being directed from 

 the exterior towards the interior, supposing the lobes to 

 have their points in contact. 



Let us now look at the margin of the disk. Here 

 are attached twenty-four slender tentacles, six in eacli 

 quadrant formed by the divergent ribs, or radiating 

 canals. Each tentacle springs from a thickened bulb, 

 which is imbedded in the margin of the disk ; it ia 

 evidently tubular, but the tube is not wider in the bulb 

 than in the filament. The general surface is rough with 

 projecting points, which in some assume a very regular 



