2 J. D. Dana on Zoophytes. 
in diameter, embellished with green or purple blossoms which 
stud t face like gems; while other hemispheres of Mean- 
drina appear as if enveloped in a network of flowering vines. 
27. It is impossible in any figures or sketches to convey an 
idea of the combined effect, where the various species are grow- 
ing together. The resemblance in form to flowers* may how- 
ever be appreciated from a few figures. In the following an Ac- 
tinia is represented in its different conditions, expanded and closed. 
Fig. 12. 
The similarity to an Aster is at once apparent, yet with this dif- 
ference, that there is an opening at the center of the disk for 
taking food. ‘The animal is fleshy throughout, and expands by 
taking in water and injecting itself and its tentacles, which be- 
ing tubular organs, receive thus some degree of rigidity ; it con- 
tracts by expelling the water again, drawing in thus the disk and 
rolling its border over the tentacl The water passes out 
partly through the mouth, often in part through a puncture at the 
tips of the tentacles, and in some species through pores in the 
sides of the animal.t The next figures represent coral animals, 
resembling, as is seen, In every essential particular, the Actinia 
above, and differing internally in nothing except the power 0 
secreting lime. Fig. 13 as well as 14 are both of the size of 
life, and the latter shows the average size of the polyps through 
the large genus Astrea. The former is a single animal from 
a large hemispherical group (a Mussa) consisting of fifty or sixty 
such polyps; and when alive, the whole forms a magnificent 
* The gorgeous character of many Actinias may be iater 
t 
ed figures on the first five Mates of the atlas to ienaty be Wane Ce ee 
ah aed te Favy ae ul pencil of Mr. J. Drayton, one of the artists of the 
i. é animals of one or more species of near! 18 0 ; 
zoophytes are figured and colored on the other plates of t aches a heel 
ar at ot be soeny, for delivery, for some months. : 
iis ast peculiarity has been supposed to belong only to tubercul ies ; 
tm fipden Sad seas ig it the genus Cribring But r. V yihaek bameend 
: pores existed in the A. marginata of the Boston h i 
rfectly smooth and semi-transpetent skin. a eee 
