J. D. Dana on Zoophytes. 15 
53. This retraction also takes place intermittedly at the base 
of the polyps in some species, giving rise to a transverse arrange- 
ment of septa, more or less regular, as shown in some Cyatho- 
phyllide, the Favosites and Pocillopore. 
54. 3. Another peculiarity in the mode of growth is deserving 
of a few words. I refer to the ready coalescence of branches. 
Some foliaceous Madrepores are made up of coalesced branch- 
lets, none of which are free excepting those at apex; and in 
others the whole is a network of united branchlets. Simple con- 
tact leads to this growing together. It is a union of the animals, 
rmed. 
We may remark separately upon the instances of lateral or an- 
ferior budding, and terminal or superior. fe 
56. A. Inferior Budding.—1. If a non-acrogenous polyp buds 
laterally at base, by a single creeping stolon, it will form a linear 
zoophyte ; but if the basal buds are given out in different direc- 
tions instead of a single line, the zoophyte will spread out in a 
broad plate, or else a net-work, according as the polyps coalesce 
laterally or not. The Xenide illustrate all these varieties; an 
they pass into one another by gradual shades. Should the 
pol grow together by their sides to their very summit, the 
thickness of the zoophyte will be equal to the height of the 
polyps; otherwise, there will be less thickness and the polyps will 
stand prominent when expanded. Both of these conditions 
are illustrated among the Zoanthide, and the gradations are so 
imperceptible that we see no propriety in retaining in this fam- 
ily this distinction as generic, though so adopted by former 
The following figure of a Gemmipora illustrates the form- 
ation of plates by lateral budding, without acrogenous growth. 
The fact that the budding is lateral is shown by the internal di- 
ee 
* The genus Palythoa should include therefore the Mammilifera of Lesucur ; see 
Report on Zoophytes, p. 423. 
