IV 



PHYLUM CCELENTERATA 



195 



Sea-anemones the only simple forms are certain Madreporarian 

 corals, such as Flabellum (Fig. 156, A, B), and three genera 'of 

 Alcyonacea, of which 

 Hartea (Fig. 145) may be 

 taken as an example. 



The simplest mode of 

 budding is that just de- 

 scribed in Zoanthus, in 

 which new zooids are 

 developed from a narrow 

 band-like or tubular stolon 

 (Fig. 144, st). A more usual 

 method resembles that 

 with which we are already 

 familiar in Hydrozoa, new 

 buds being formed as lateral 

 out-growths, and a tree-like 



Colony arising with numer- JT IG . 144 Zoanthus sociatus. A, entire colony ; 



nn vnnirlci rrinrrinrr frrkm a st - stolon. B, transverse section, sgph. siphono- 



5 springing irom a glyphes ; d. d. dorsal, and v. d. ventral directive 



Common Stem Or COSnOSarC. mesenteries. (After McMurrich and Korschelt and 



Corallium and Gorgonia 



(Figs. 146 and 155) are good examples of this type of growth. In 

 other cases the buds grow more or less parallel with one another, 



producing massive colonies 

 either of close-set zooids or of 

 zooids separated by a solid 

 coenosarc. As examples of this 

 type we may take Palythoa, the 

 most complex of the Actiniaria, 

 and many of the common 

 Madreporaria, such as Astpcea 

 (Fig. 147). In the Sea-pens 

 (Pennatulacea) the proximal end 

 of the elongated colony (Fig. 

 148) is sunk in the mud, and 

 the distal end bears zooids 

 springing either directly from 

 the cosnosarc or, as in Penna- 

 tula itself, from flattened lateral 

 branches. The stem itself is 

 the equivalent of a polype. 



A very peculiar mode of bud- 

 ding occurs in the Organ-pipe 

 \ 'jj$T3P Coral (Tubipora). The base of 



^Kk^ the original polype (Fig. 149) 



FIG. 145. Hartea elegans. gul. gullet;; grOWS Out into a flattened CX- 

 ("Ser'pIrS W^* 3 ' '' ^^^ P ansion fl m which neW P^P 68 



o 2 



