464 



PROCEEDINGS OF THE AMERICAN ACADEiMY. 



The Bermuda hydroids show a close relationship to those of the 

 West Indies and the Gulf of Mexico, All the genera of the new species 

 and all but one of the species previously described are there represented. 

 The remaining species, Bimeria humilis, has not to my knowledge 

 been found south of New England. 



Genus PENNARIA McCrady. 

 Pennaria tiarella McCrady. 



The Pennaria tiarella of Bermuda 

 has on the average three more filiform 

 tentacles than that of Wood's Hole, 

 Mass. Clarke ('79) described a member 

 of this genus from Cuba, under the name 

 of P. symmetrica, in which the gonosome 

 was lacking. The characters which he 

 considers specifically distinctive are : the 

 exact form of the hydranth, the origin 

 of the tentacles from a little above the 

 base, and the presence of eighteen fili- 

 form tentacles. The first two characters 

 vary greatly with age and the amount of 

 food in the hydranth. The number of 

 tentacles does not seem to me of specific 

 importance, because it varies considerably, 

 owing only in part, I think, to the degree 

 of maturity. It seems probable that P. 

 symmetrica, like the Bermuda form, is a 

 geographical variety of P. tiarella. 



Genus EUDENDRIUM Ehrenberg (in 



part), 18:52. 



Budendrium ramosum Linnaeus. 



E. ramosum differs in three respects 

 from the individuals of Wood's Hole, 

 Mass. There is a slightly larger aver- 

 FiGURE 1. Colony of Eudendrium age number of tentacles ; there may be 

 hargitti (xiO). one more lobe to the male gonophore ; 



the hydranth to which the clusters are 

 attached is often entirely aborted. 



