ORDERACTINOIDEA. 79 



new series of polyps developing successively near the margin : the 

 same foliaceous corals often form elongating processes or stems. One 

 or more polyps at a point in a folium begin to bud and grow prolately 

 upward; and bud follows bud, until the protuberance becomes a branch. 

 This may be seen in some foliaceous Merulinse,* and the ramose 

 species are other examples of the same. 



c. These ramose species branch, either by furcation or by lateral 

 shoots. The latter process does not differ from that just described. 

 In the former, the polyps at apex commence simultaneously two or 

 more lines of buds, which lengthen out in the cumulate manner 

 elucidated. This same principle is illustrated in many Meandrine 

 corals. The lines of polyps, as above stated, result from a succes- 

 sion of buds in a single series. These lines frequently furcate or 

 give out lateral branches ; the polyp, at the extremity of a line, by 

 originating side-buds, each commencing a separate series, produces 

 thus the furcation. The margin of almost any Meandrina, or of the 

 folium of a Merulina, affords examples of this. The process is con- 

 nected with the increasing breadth of the margin, like the marginal 

 growth and budding of an Astrsea. 



In the foliate corals, the folia are constantly subdividing or be- 

 coming lobed, on the principle explained in the latter part of 74 a.f 



80. Relation of the Astrceidce to the recent CaryophyUidce. The 

 distinction in the mode of budding, and the prominent peculiarities 

 of their coralla, as laid down ( 48), seem to draw a wide line of 

 division between the Astrseidse and Caryophyllidse. Yet, as in other 

 departments of nature, there are in fact no such lines ; gradual transi- 

 tions, much to the annoyance of the systematist, link the whole 

 together. By observing the transitions, we may distinguish more 

 definitely where the distinctions actually lie. The Astrsas, which 

 commence this transition, instead of budding from near the centre of 

 the parent, or its summit disk, give out buds exterior to the same, as 

 in the A. argus. The polyps differ commonly from those of other 

 Astraas, in being more prominent above the general surface, and the 

 aggregated individuals are not coalescent so nearly to their summits. 

 The interstices are lamello-striate as before, though hardly as promi- 

 nently so. Following down the transition, we find certain species 

 (A. microphthalma and A. ocellina) in which the polyps stand their 

 diameter in height above the general surface. The union of the 



* Plate 15, figure 1. f See the remarks under the genus Pavonia. 



