66 THE TENTACLES. 



protriisile, and when the little animal is active are 

 contimially being thrust out in various directions, 

 sometimes everted, but more cfommonly 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 pei-petually 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 organised animals. The substance of 

 this foot appears to be delicately granular ; but there 

 is a very manifest tendency 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 each 

 quadrant formed by the divergent ribs ; but in some 

 specimens I could not count more than twenty-three. 

 Each tentacle springs from a thickened bulb, which is 

 imbedded iii the margin of the disk : it is evidently 

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

 the filament. The general surface is rough wdth pro- 

 jecting points, wdiich in some assume a \ery regular 

 muricate appearance (as shown at 7), and the tentacle 

 terminates in a blunt point. The discal part of the 

 bulb is fringed with a row of minute bead-like glands. 

 Around the edge of the circumference of the disk, on 

 the exterior, are arranged eight beautiful organs, 

 which are doubtless the seats of a special sense. 

 They are placed in pairs, each pair being approximate, 

 and appropriated to each of the quadratures of the 



