HTDROZOA. 91 



uous Species. Examples of this habit are afforded 

 Fig. 1 8. 



i 



Morphology of Sertltlaeiad^ : — a, dried hydrosoma of Sertu- 

 laria tricuspidata ; b, portion of the same ; c, fragment of the 

 ccenosarc from a dead specimen of Halecium kalecinum ; d, gono- 

 blastidium of H. Beanii ; e, three gonoblastidia of Sertularia 

 argentca ; — ir', hydrotheca; k, ccenosarc; p\ gonoblastidium, 

 (All, except a, magnified.) 



by the genera Coppinia and Reticularia, and by 

 several of the true Sertularice, 



