472 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



Trophosome. Minute white colonies, seldom ten millimeters long, 

 arising rather sparsely from a creeping stolon, bearing a deeply cam- 

 panulate hydrotheca, pedicel annulated most commonly at both ends, 

 (Figure 14), hydrothecae only one and one-third to twice as long as 

 wide, the proportion depending on the age and condition of expansion 

 of hydranth. Ten to twelve triangular teeth, more or less rounded and 



of varying proportions. Wall 

 of hydrotheca thickened below 

 hydranth to form a spheroidal 

 cavity. Hydranth of usual 

 type with twenty to twenty- 

 four tentacles. 



Gonosome. Gonothecae aris- 

 ing from stolons, sessile, twice 

 as long as hydrothecae, ovoid 

 and flattened, distal end trun- 

 cate and flaring, and of one 

 half to two thirds the diame- 

 ter of the gonothecae (Figure 

 15). About eight medusa buds 

 are attached along the blasto- 

 style, of which the most mature 

 are campanulate in form with 

 four tentacles and four other 

 rudimentary organs interra- 

 dial in position. The manu- 

 brium may occupy half the 

 space within the bell, is nearly 

 spherical, and apparently not 

 provided with any terminal 

 lobes. 

 This Clytia combines the unbranched habit of C. hicophora and 

 C. grayi with the non-annulated or weakly annulated gonosome of C. 

 cyUndrica. The teeth of the hydrothecae are less pointed than those 

 of C. bicophora, and, though as rounded as those of C. grayi, are much 

 more deeply cut. The specific name " simplex " is suggested by the 

 marked simplicity in the form of trophosome and gonosome. 



Genus HALECIUM Oken, 1815. 



Halecium bermudense (new species). Figures 16-20. 



The hydroid occurs in those places along the shores of Bermuda 

 which are most frequented by related species. 



Figures 14, 15. Clytia simplex. 



Figure 14. An individual (X 18). 

 Figure 15. Gonotheca (X 60). 



