78 INVERTEBRATE ANIMALS. 
sometimes floated to our own coasts. It is about two inches in 
length by one and a half in height. The proximal end of the 
coenosarc is greatly expanded and flattened out into an oval 
disc, which carries a vertical triangular crest, runing obliquely 
across its upper surface (fig. 24, 46). The whole organism is 
semi-transparent and of a beautiful bluish colour, and it floats 
at the surface of the sea with the vertical crest exposed to the 
2800 299 F000. 9195545 NN 
EAN 
& 
288 8 2 OcGonpacofese 
vee i. 
ty 
Fhe 2 Vy, 
or) wn Phy, 
Fig. 24.—a Portuguese man-of-war (after Huxley); 
6 Velella vulgaris (after Gosse). 
influence of the wind, and thus officiating as a sail. From the 
under surface of the disc are suspended the various appendages 
of the organism, consisting of a single large central polypite, a 
number of processes, like polypites in shape, and carrying 
medusiform gonophores; and lastly, a single series of ten- 
tacles which arise from the ccenosarc quite independently of 
the polypites. 
