138 Natural History Bulletin*. 



It is indicated in PL IV, tig. 5, as a sliaded line below end of 

 reference line, a. These shaded lines should be a little nearer 

 the bases of the tentacles. 



The tentacular muscles are also extensions of a portion of 

 each retractor as described in Briaraun. 



The polyps in this species are capable of retracting farther 

 within the calicle than in any other studied. 



Gastric filaments. In the living specimens, these appear as 

 white, excessively convoluted, and densely ciliated threads, 

 forming a conspicuous object when part of the calicle wall is 

 dissected away. As their name implies they are thought ta 

 be concerned in digestion. The}' appear to be four in num- 

 ber, but they are so contorted and easily broken in alcoholic 

 specimens that it is difficult to count them. PI. V, fig. 4, 

 represents a longitudinal section of a polyp. The gastric fila- 

 ment (h, h) is seen to be attached to the lower end of the 

 gullet and to extend in a tortuous course down to where the 

 bottom of the calicle should be. Toward the lower end of 

 its course, it appears to break up into a number of branches 

 which have horseshoe-shaped terminations. 



Three of these branches with their terminations are shown 

 in PI. V, fig. II. It will be seen that each of these horse- 

 shoe-shaped terminations has its concavity lined with some- 

 what columnar cells backed by large nucleated cells, an ar- 

 rangement somewhat similar to that of the gullet lining. 

 Perhaps these horseshoe-shaped structures may be the organs 

 which secrete digestive fluids; but if we were to judge solely 

 by appearances, the gullet lining, PL V, fig. 3, seems to pre- 

 sent an appearance more like that of a gastric surface. I am 

 aware, however, that authorities do not consider the gullet as 

 digestive in function. 



The ova are very numerous in sections secured from this 

 species. They were found m various stages of development 

 from exceedingly small ova to those which had apparently 

 reached the planula stage. PL V, figs. 5, 6, 7, 8,9, 10, 12, 

 show various ova of this species. In fresh specimens they 



