62 
GUIDE TO THE CORAL GALLERY. 
Physah'a floating on the surface ; cr , crest ; p, a polyp ; pn , air sac. (After 
Huxley; from Parker and Haswell’s Zoology.) 
sac takes the form of a large pear-shaped bladder provided with a 
many-chambered crest ; a mass of generative buds and feeding polyps 
with long tentacles is suspended from the under surface of the 
Case 3, the last having attached to its stalk a long tentacle armed with 
Upright part, thread-cells. 
In Physalia , the “ Portuguese Man-of-War ” (Fig. 25), the air- 
Fig. 25. 
