EXPLANATION TO PLATE I. 



Fie;. 1. fii'iitiliirin jiiniiiln Limueus. Portion of main stem and branches (enlarged |. 

 '_'. Serlularia pumila. Side view of branch, showing gonangium (enlarged). 

 :;. Si -rtiihn-lii jiitniil/i. Pair of hydrothene and expanded hydranth (greatly enlarged) 



4. Hci-liilin'iii I'l'ivlin/xi Nutting. Portion of main stem and branches (enlarged). 



5. Si'i'liiliiriii.mvliii/xi. Part of branch (enlarged). 



('.. ti'i-liiliiriti ivrdiiitxi. Branch from another colony (enlarged). 



7, S, !l. St'iiiiliii-iii i-i'i'diti/xi. Pair* of hydrothccvc (greatly enlarged). 



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