146 



ZOOLOGY 



SECT. 



and four knobbed tentacles; from the dactylopores long, filamentous, 

 mouthless dactylozooids or feelers (D.Z\ with irregularly disposed 

 tentacles : the function of these latter is probably protective and 

 tactile, like that of the guard-polypes of Phimularia and the 

 dactylozooids of Hydractinia. The bases of the zooids are con- 

 nected with a system of delicate tubes, which ramify through the 

 canals of the coral, and represent a much-branched coenosarc, 

 recalling that of Hydractinia (p. 134). 



'^f&r&JIm m 



-VT*f :!teA^M 



end eef 



FIG. 104. Millepora. Diagrammatic view of a portion of the living animal, partly from the 

 surface, partly in vertical section. In the sectional part the ectoderm is dotted, the endoderm 

 striated, and the skeleton black, ect. ectoderm ; end. endoderm ; d.p. dactylopore ; D.Z. 

 dactylozooid ; g.p. gastropore ; mth. mouth ; P. polype ; t. tentacle. (Altered from Moseley.) 



The ccenosarcal tubes have the usual structure, consisting of 

 ectoderm and endoderm, with an intervening mesoglcea. From 

 the relative position of the parts it will be obvious that the cal- 

 careous skeleton is in contact throughout with the ectoderm of the 

 colony : it is, in fact, like the horny perisarc of the Leptolinaa, a 

 cuticular product of the ectoderm. 



The only other genus to which we shall refer is Stylastcr (Fig. 

 105), which forms a remarkably elegant tree-like colony, abund- 

 antly branched in one plane, and of a deep pink colour. On the 



