1 1 2 PHYSALI1DJE. PAKT in. 



outer one dense, thick, and elastic, the inner formed of 

 delicate fibres and lined with cilia. The air-sac is only 

 attached to one part of the interior ; and there it com- 

 municates with the exterior by a small aperture, which 

 may be seen at about half an inch from the pointed apex 

 of the animal. The body is several inches long, of a 



Fig. 121. The Physalia. 



delicate pale green colour, passing gradually into dark 

 indigo blue on the under-surface ; the ridge of the crest 

 is tipped with dark crimson, and the pointed end is 

 stained with deep bluish green. 



The appendages, which hang down from the inferior 

 and thick part of the body, are large and small branch- 



