152 Natural History Bulletin. 



The stolon or root stalk is expanded to form a surface by 

 which the zoanthodeme is attached to the bottom or some 

 stationary object. 



Color a golden yellow, uniform throughout. Specimens 

 which have been kept for sixteen months in strong alcohol 

 have not perceptibly faded. 



Size smaller than that of the red sea-fan which it very 

 closely resembles in structure. The largest specimens which 

 I have seen were not more than two feet in height, while the 

 red form sometimes reaches a height of nearly four feet. The 

 yellow form seems to prefer sandy bottom, while the red is 

 more often found attached to coral rocks and dead coral. 



Calicles included, almost globular. (See PI. X, figs. 5 and 6). 



Polyps dark brown in color, completely retractile, although 

 they often die partially expanded as illustrated in PI. X, fig. 3. 

 They seem to be quite sluggish, in which respect they resem- 

 ble those of Muricea. The polyps are most numerous on the 

 fiat sides of the branches, i. e., the sides within the meshes of 

 the net work at right angles to the general plane of the 

 zoanthodeme. There are also many polyps on the side of the 

 fan which does not bear the numerous curved branchlets. 



The tentacles are moderately long, contain few or no 

 spicules, and are furnished with long and prominent papillae 

 which are larger in proportion to the size of the polyp than 

 those of any other species examined,' and present a picture of 

 gracefulness when viewed alive under the microscope. 



In retraction the tentacles fold inward and downward and 

 are snugly packed away in the sack formed by the invagin- 

 ated body wall much as is the case in Briareum. The 

 ultimate flexure near the tip is inward and upward so that the 

 tips of the tentacles in the retracted polyp are clustered 

 together immediately above the mouth and point upward. 

 It will thus be seen that each tentacle assumes an S-shaped 

 position when retracted, while those of Briareum are coiled. 



I The reader must not be misled by fig, 3, PI. X, which represents a polyp 

 only partially expanded and has the tentacles still incurved. 



