19 



fic(|ucii(ly forjiUMl in llic oldcM- colonies. Tliis 

 Hg'Uic is drawn from ;i spcciiucii in I ho 

 Caniliridii'e ^Inscinn. 



Yig. ■!. \ ('ili(>al section Uiroug-li a portion of a eolonv 

 (senii-diag'raniniatic) to sliow the antliocodia 

 in different stages of retraction, the diifereiit 

 sizes of the ])olyps, the general arrangement 

 of the canal system, the position of the 

 spicules, &.C. The mesenterial filaments are 

 lepresented as being in the same plane as the 

 tentacles, which they are not, in order (o 

 illustrate certain points in their relations. 

 The following points aie illustrated in this 

 figure:!' represents the fully - expauih'd 

 anthocodia of a polyp, 2' represents a par- 

 tially retracted antliocodia in which the 

 tentacles are contracted and folded inwards 

 towards the mouth, the body-wall forms a 

 circular fold over the ciown of tentacles, 

 'J' repiesents an anthocodia in which the 

 tentacles and stomodaeum have sunk to the 

 level of the general surface of the colony, 

 4' an anthocodia which has sunk below the 

 surface, and 5' an anthocodia completely 

 retracted, the false mouth having closed. It 

 will be noticed that the long (dorsal) mesen- 

 terial filaments are represented as being all 

 on the left side of the j^olyps. This indicates 

 that the axis of the l()i)e from which the 

 section Avas made was on the left side of the 

 drawing. 



Fig. 4. A fully-expanded anthocodia drawn from a 

 living specimen at Plymouth. The bases of 

 the tentacles are extended in a bullate 



