49 



rhe individual calyces are verruciform or dome-shaped, 1.5 mm. high and 2 mm. broad 

 at the bases. The polyps are entirely retractile, the margin closing in around them so as to 

 leave but a smal] aperture. The calyx walls are covered with small oval scales or plates which 

 have a darker centre and a lighter margin. They are imbricated near the margins, but seem 

 Lo be separated on the lower parts of the calyx. The operculum is of the same type as in 

 the last species, and the collaret is well marked. 



Spicules. These are less symmetrical than in the last species, but the typical Bebryce 

 form is common, consisting of a thick warty disc from the centre of which arises a warty 

 mass of varying shape and size, much more irregular than in B. hicksoni: The disc has a 

 jagged outline which in many cases becomes star-shaped, multiradiate or cruciform. 



Sometimes the whole spicule is rudely dumb-bell-shaped, and at others it takes the form 

 of a doublé star. 



C o 1 o r. The colony is dark purplish brown, with a vinaceous tinge. The spicules are colorless. 



General distribution. The type was taken from the Gulf of Manaar. 



This species, although secured at tvvo of the same stations as the preceding, is very 

 distinct, especially in color and the shape of the spicules. 



3. Bebryce thomsoni new species. (Plate VII, figs. 4, 4a; Plate XX, fig. 8). 



Stat. 50. Bay of Badjo. West coast of Flores. Up to 40 meters. Mud and sand. 

 Stat. 258. Tual anchorage, Kei Islands. Down to 22 meters. Lithothamnion. 

 Stat. 260. 5°3Ó'.5S., I32°55'.2E. Kei Islands. 90 meters. Sand, coral and shells. 



Colony closely branching, pinnate in form, 5.7 cm. in height and with a spread of 3 cm. 

 The main stem is straight and rigid, and sends forth an undivided branch 3.8 cm. from its 

 base, another one 3 cm. above the first and on the opposite side, and still another on the 

 same side as the first and 6 mm. above it. Each of the two upper branches gives off a short 

 side branch near the end. The stem and branches are round and about 1.2 mm. in diameter. 

 The calyces are distributed mainly on three sides of the colony, and are about 1.5 mm. apart, 

 on the average. 



1 he individual calyces are almost entirely included, being represented by slight swellings 

 only, and these are oval in section, their longest diameter being 2 mm. at the base. Their 

 walls are filled with imbricating discs which often seem to be arrangfed in regailar transverse 

 rows or whorls, and have ctenate edges. The whole colony is covered with a thin coating of 

 sponge which greatly obscures the details. The polyps are entirely retractile, and the calyx 

 closes over them so as to obliterate the opening. The details of the operculum are very diffi- 

 cult to ascertain. It seems to be of the ordinary pattern, but composed of very slender spindles. 



Spicules. These are remarkably uniform in size and structure, being small round 

 bodies, each covered with smooth bead-like tubercles, and each bearing a comparatively large 

 elevated disc-shaped body rising from its centre and attached to it by a very short peduncle. 

 The shape of the entire spicule is much like that of a mushroom with an expanded disc-shaped 



SIBOGA-EXPEDITIE XIII b, 7 



