94 

 g. Hctcrogorgia operculata new species. (Plate XVIII, figs. i, ia). 



Stat. i ij. i°o'.5 S., 122° 56' E. Kwandang Bay entrance, North Celebes. 80 meters. Sand and coral. 



Colony flabellate and reticulate, 33 cm. in height and with a spread of 29 cm. The 

 width of the colonv would be much greater but for the fact that a part of the specimen is 

 folded over across the front, and anastomoses with it. The main stem divides about 3 cm. from 

 its base into two main branches, and these anastomose in a meshwork in such a way that 

 they can not successfully be traced. The web is rather loose, and the branches delicate, averaging 

 about 2 mm. in diameter. The proximal portion of the main branches are compressed, and the 

 remainder of the branches are round in section. The calyces are thickly emplanted over the 

 whole surface of the colony. 



The individual calyces are low, dome-shaped verrucae, about 1.5 mm. in diameter. Their 

 walls are filled with the erect projecting points of radiate spicules, the points forming more or 

 less regular whorls around the calyx. walls. The margins are crowned with a circlet of blunt 

 points. The polyps are completely retractile and the operculum is composed of two relatively 

 heavy spindles lying almost paralell to each other on the dorsum of each tentacle, with a third, 

 shorter, one between their bases. The collaret is strono-, consistine of several rows of encircline 

 spindles. 



Spicules. As is usual in this genus the spicules are mainly stellate forms. Few of 

 them, however, are very symmetrical stars. There are also many crosses, butterfly-shaped forms, 

 multiradiate spicules, and a few rather slender curved spindles. 



C o 1 o r. The colony is a dull orange, or bright terracotta. The axis is a strong, dark 

 olive brown, lightening distally, and the spicules are orange. 



This handsome species differs greatly in color from any of the other specimens of 

 Hctcrogorgia in the Siboga collection. Although superficially resembling other reticulate species 

 of the genus, it differs from H. magna in its heavy operculum and collaret ; from H. ramosa 

 in color, and in the fact that the latter species has large tuberculate spindles ; from H. rcticnlata 

 in color and character of the spicules, there being no butterfly-shaped forms in the last 

 mentioned species. 



