68 CORALS AND CORAL ISLANDS. 
object. The accompanying figures of the animal are from the 
drawings made to illustrate a yet unpublished memoir by 
Prot. Agassiz. They are copied from the “Sea-Side Studies ” 
of Mrs. Agassiz and Alexander Agassiz. In fig. c, the polyps 
are of the natural size, while fig. @ represents one of them en- 
larged. The polyps, as is observed, stand very prominent 
above the cells of the corallum, because only the bases of 
them secrete coral; and the buds, which open between the 
ealicles, are hence lateral buds; the coral has much resem- 
blance to that of an Orbicella, in which budding is margin- 
c 
~ WW (i 
\ AN 
pW 

ASTRANGIA DANA, AG. 
al. The tentacles have minute warty prominences over 
them, which are full of lasso-cells. each about a 500th of an 
inch in length, or about two-thirds larger than those of the 
white cords that edge the internal septa. ‘The corallum, 
though massive, is somewhat irregularly lobed above, and 
grows to a diameter of two or three inches. It is covered 
with stars an eighth of an inch to a sixth across (fig. 6), which 
are usually crowded together, the intervening wall being very 
thin and solid. ‘The author alluded to the crowd of stars in 
the name Pleiadia, which he proposed for the genus in his 
Report on Zocphytes (p. 722). 
The genus Cladocora, containing slenderly branching ra- 
