io6 



MANUAL OF ZOOLOGY 



SECT. 



cr- 



FIG. 48 Physalia. The living animal 

 floating on the surface of the sea. cr, 

 crest ; p, polype ; pn, pneumatophore, 

 float, or air-sac. (After Huxley.) 



FIG. 49. Physalia arethusa, natural 

 size. (After Agassiz.) 



