6i 



being composed of a richly branched and exfoliated basal part from which arises a long 

 thorn-like projection which, in this species, is covered with fine serrations, and projects 

 upward and outward from the calyx walls when in situ. There are also the bowed spindels 

 of the operculum, besides regular spindles, triradiate and quadriradiate forms and a few 

 small Stachelplatten. 



Color. The ccenenchyma and polyps are rich sienna brown, the spicules are colorless, 

 but appear white when in situ and seen by reflected light. 



This is a very striking form, quite different in color from any other species of the 

 genus Echinomuricea that I have seen. 



& 



-. Echinomuricea costata new species. (Plate X, figs. i, ia-, Plate XXI, fig. 8). 

 Stat. 297. 10° 39' S., i23°4o'E. Timor Sea. 520 meters. Mud. 



The type specimen is incomplete and much broken up by the tangles. It is 13 cm. in 

 height and has a spread of 14.5 cm. 2.5 cm from its base it divides into two main branches, 

 and these again divide into two each about 1 cm. from their origin. One of these secondary 

 branches sends forth four branchlets from its outer side at intervals averaging about 5 cm., 

 there being but one branchlet on the opposite side. A nother fork of the main branch gives 

 off five branchlets from its outer side. The other secondary branches are irregular in their 

 branching, branchlets of the qth and 5th order being produced. All of the branches tend to 

 curve upward like candalabra. The branches terminate in polyps. The calyces are thickly 

 emplanted on all sides of the branches, but are more closely crowded laterally, where they 

 are about 2 mm. apart. 



The individual calyces are in the form of short cylinders or truncated cones. They are 

 about 1.2 mm. in height and 1.7 mm. broad at the margin. Their sides are armed with 

 jagged points projecting vertically, their roughened ends reaching beyond the margins and their 

 jagged sides are ornamented with spinules, which produce rib-like eftects on the calyx walls. 

 There are often a few horizontally disposed spindles around the bases of the calyces. The 

 collaret of the polyps is very heavy, and the operculum arises above it in a regular cone 

 cornposed of two comparatively heavy, longitudinal spindles reaching from the collaret to the 

 apex of the cone. 



Spicules. The most conspicuous type is the heavy, warty spindle with toliaceous 

 base, characteristic of the genus Echino)>mricea. There are also a few of the Thesea type of 

 unilateral spindles. Regular spindles and triradiate forms are also seen. 



Color. The specimen, when clear of debris and tangle material, is a yellowish brown. 

 The spicules are colorless. 



This species shows an approximation to the genus Thesea in having a few of the 

 Thesea type of spicules, but these are much less numerous and conspicuous than those of the 

 regular EcJiinoimiricca type. 



