J. D, Dana on Zoophytes. ai 
ist in the enlarged disk; and at the extremity of the other, fur- 
cation has commenced. The subdivision is a consequence of the 
growth and budding ; and as it takes place at nearly uniform 7n- 
tervals, and depends on the fact that the polyps have normal lim- 
its of size, the resulting zoophytes are generally very regularly 
hemispherical in form; moreover the branches in all individuals 
of the same species are very nearly alike in size and in the in- 
tervals which separate them. 'These characters therefore afford 
important specific distinctions. 
77. Other species branch by a succession of buds, nearly as in 
the Oculine. This is the case with the Meruline, and may 
seen in the branch-like processes over foliaceous species, as well 
as in the ramose species. 
78. From the facts which have been presented, it appears that 
the distinction of swperior and inferior gemmation and growt 
therefore consists in the disks widening by growth in some species, 
and in others the parts just exterior to the disks,—a_peculiarity 
d it will be perceived that the subject receives increased in- 
terest from the illustrations it affords of corresponding facts in 
* Ehrenberg places the Astrea argus, a foliated Gemmipora and some other 
species in the same genus, to which he has applied Lamarck’s name, Explanaria. 
t Other distinguishing characters will be hereafter given. 
