collarets on the calyx margin. The collaret is composed of 8 to 10 rows of transverse spindles, 

 the upper two or three rows curved, so that they form an en chevron arrangement on the 

 tentacle bases. Still higher up on the basal part of the tentacles the spicules are arranged in 

 longitudinal groups, one to each tentacle, each group forming a jagged point. Above these 

 points the tentacles curve inward and their dorsal surfaces are armed with a double row of 

 slender spindles, each row extending from near the mid-dorsal surface of a tentacle to near 

 the pinnule bases. 



A cross section of a stem shows a comparatively thin coenenchyma with an ill-defined 

 circlet of water-vascular canals around the periphery of the axis. The axis is composed of very 

 slender rod-like or needle-like spindles with distant thorny points immersed in a horny matrix, 

 and is penetrated with conspicuous water-vascular canals of irregular size. 



Spicules. Those of the coenenchyma of the stem are small, rounded, disk-like, or 

 compact irregular forms with prominent and irregularly disposed verrucse. Those in the axis are 

 very slender rod-like forms which are smooth on the greater part of their surface, bearing 

 distant thorny points and longitudinally disposed, forming a felted mass immersed in a horny 

 matrix. The spicules of the ccenenchyma of the branches and of the calyx walls are mainly 

 spindles of various forms, usually with irregularly disposed verrucae. All intergradations between 

 the forms described above are seen. 



Color. The colony is light yellowish brown or tan color. 



This species differs from all the others described in this genus in having all of the 

 branches solid and without tunnels or belts inhabited by symbiotic crustaceans. 



A label in the jar in which this specimen was found bears the word ^Spongioderma'} 

 In all essential characters, however, it seems to be a Solenocaulon. The axis is penetrated by 

 conspicuous water-vascular canals, and this character would prevent its being placed in the 

 * Spongioderminte" of WRIGHT and STUDER. 



Some fragments from station 142 are referred with doubt to this species. They are 

 evidently from a young specimen. The stem and basal parts of branches are grooved and show 

 a tendency to flattening. The calyces are rather distant and prominent. The polyps agree with 

 the type in spiculation. 



4. Solenocaulon jedanensis new species. (Plate II, figs, i, i; Plate XI, fig. 2). 



Stat. 164. i42'.5 S., i3O47'.5 E. 32 meters. Sand, small stones and shells. 

 Stat. 273. Anchorage off Pulu Jedan, East Coast of Aru Islands. 13 meters. Sand and shells. 

 (Type locality). 



Colony (base lacking) pinnate in general form, 16.5 cm. in height and with a spread 

 of 4.8 cm. The main stem is oval in section, measuring 1 1 X 8 mm. 4.6 cm. above its proximal 

 end it becomes tubular and gives off short tubular branches ending in small flattened, some- 

 times round, twigs. The tubular part of the main stem is compressed; but 9.4 cm. from its 

 base it looses its tubular character and becomes alternately deeply channeled and belted, 

 there being three belts about i cm. broad and three deeply channeled portions. The branches 



SIBOGA-EXPED1TIE XIII b*.- 2 



