164 



ZOOLOGY 



SECT. 



sometimes several feet in length and containing batteries of 

 stinging-capsules powerful enough to sting the hand as severely 

 as a nettle. The male reproductive zooid remains attached, as in 



) I 



Fig. 122. — Physalia : the living animal floating on the sux-face of the sea, cr. crest ; p. polype ; 

 pii. pneumatophure ; t. tentacle. (After Hu.xley.) 



Halistemma, but the female apparently becomes detached as a 

 free medusa. 



In Diphycs the float is absent. Two swimming-bells (Fig. 12SA, m) 

 of proportionally immense size are situated at the proximal end 

 of the eoensarc, and are followed by widely-separated groups of 

 /ooids {B), each group containing a polype (w) with its tentacles {i), 



