NANOMIA CARA. 



205 



this kind of tentacles arc sole-shaped bodies, paved with a beautifully 

 arranged setting of large lasso-cells, edged in by a large set running 

 round the edge (Fig. 339) ; these knobs are partly hollow, a portion of 

 the tube of the tentacle extending into it a short distance. 



The second kind of feeding polyps (Medusae) (Fig. 340) resemble 

 the first in every respect except the tentacles ; they are, like them, 

 attached to the main axis, and protected by a scale, omitted in the 

 figure ; at the proximal end of the polyp we find, however, a cluster of 

 tentacles of a totally dift'erent nature from the club-bearing lashes of 

 the first kind ; they take their origin as diverticula of the wall of the 

 polyp, as those of the first kind ; they never grow long, scarcely 

 extending the length of the polyp, but are twisted closely when fully 

 developed, though in their eai'lier stages they are more corkscrew- 

 shaped, and coiled quite loosely. The whole surface of these tentacles 



Fig. 311. 



Fig. 339. 



is covered by a regular pavement of lasso-cells of the same size ; the 

 lasso-cells in the young tentacles are only found on the edge ; as they 

 increase in length, the tentacles become more thickly covered, until, 

 when closely coiled, they have the pavement described above. There 

 are generally from five to six (Fig. 340) of these large tentacles, and 

 about as many more, in different stages of development, at the base of 

 each of these polyps ; while of the first kind of tentacles we rarely 

 find more than three long threads, though there is a thick cluster of 

 embryonic ones adjoining them ready to develop and take their place 

 if any accident should hap])en to the longer meshes. 



The third kind of polyp (Medusa'), which is found along the axi.s, are 

 polyps with closed extremities (Fig. 341), differing besides from the 

 others in having only one long, slender tentacle at the proximal ex- 

 Fig. 339. Enlarged view of tlio knob of a tentacle of the first kind of Medusic. 

 Fig. 340. The second kind of Medusa-, having cork -shaped tentacles. The scales In this and 

 following figure arc omitted ; they dill'er in no respect from those of Fig. 3:!S. 



Fig. 341. Third kind of Medusa, having only a single thread-like teiitacle, and a closed pro- 

 boscis. 



