ADDENDA. 



See Text, Page 32. 

 Plumularia geminata. 



Between the present species and the Pliimula)ia catharina Johnston there 

 is a close relation. The form of the hydrotheca, of the gonangia with 

 their basal nematophores, and of the internodes in the ultimate ramuli, is 

 very similar in the two species, while between the same parts in Plumu- 

 laria catharina and Ilonostcechas dichotoma (see p. 37) a corresponding identity 

 of form will be found. 



Foot-note to Page 49. 



I am indebted to Miss Gatty for an opportunity of examining a second species of tlie same remarkable 

 form, which may well constitute a subgenus of Aglaophenia. From Aglaophenia perpusilla this differs 

 chiefly in the width of the keel which runs down the front of the hydrotheca, and in the presence of a 

 shallow constriction between that portion of the hydrotheca which lies at the proximal side of the 

 strong intrathecal ridge and that which lies at the distal side. A decided bithalamic character is 

 thus given to the hydrotheca. The specimens scarcely surpass A. perpusilla in size. They are from 

 the Gulf of Mexico, are attached to Gulf Weed, and are destitute of gonosome. I have assigned to 

 the species the name of A. late-carinala. 



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