i8 



its base the main stem sends off two opposite branches each bearing branches which themselves 

 bear lateral twigs irregularly spaced. Branches of the 4 th order are sometimes produced, 

 main stem, after giving off these branches, continues upward in a wavy course giving off a few 

 lateral branches and ultimate twigs to its distal end. These laterals are very unevenly spaced, 

 but average about 5 mm. apart. Diameter of main stem 5.5 mm., of the lateral twigs 2 mm. 

 The stem and main branches have even surfaces, there being no swellings nor constrictions at 

 the nodes. Proximally the horny nodes are longer than the calcareous internodes, the former 

 being 2.7 mm. long, and the latter 2 mm. Above the origins of the branches, however, the 

 internodes are the longer, being 5.5 mm. long, while the nodes are but 2.2 mm. long. Both 

 nodes and internodes are rather deeply grooved in the main stem, the grooves being numerous 

 and parallel. The -branches spring from the calcareous internodes. The polyps are small, and 

 are emplanted on all sides of the larger branches, but tend to be lateral on the smaller twigs. 

 Sometimes, however, they are on all sides, even to the tips of the ultimate branchlets. 



The specimen is so completely covered with a parasitic sponge with small needle-like 

 spicules that the details of the individual calyces are hard to ascertain. The calyces are small, 

 and shaped like a truncated cone; or else are dome-shaped verrucae. A typical one measures 

 1.3 mm. in height and i.i mm. in diameter. The calyx walls are covered with a mosaic of 

 scale-like spicules with ctenate edges nicely fitted together and without regular arrangement in 

 either vertical or transverse rows. The polyp is completely retractile. There are a few very 

 small scales or calcareous granules on the dorsal surface of the tentacles. 



Spicules. These are all small, oval or irregular scales, which are densely covered with 

 relatively large tubercles. Occasionally they are somewhat branched, but not extensively so, and 

 the branches are short. Occasionally, also, double heads are seen, and very rarely collar-button 

 forms such as are found in the muriceid genus Bebryce. Ccenenchyma covered with similar scales. 



Color. The entire colony is a light straw yellow in color, probably brighter yellow in life. 



2. Mopsea alba new species. (Plate IV, figs. 2, 2; Plate VI, fig. 4). 



Stat. 156. o 29'.2 S., i3O5'.3E. 469 meters. Coarse sand and broken shells. 



Colony flabellate in form, attaining a height of 15 mm., and a spread of 20 mm. The 

 main stem arises from a disk-like base and contains one short, unbranched internode 1.2 mm. 

 in length. The other internodes bear branches, except the distal one which is very slender and 

 short. These internodes are 3.5 mm., 8 mm., and 2.9 mm. long, going from the 2 nd to the 

 4 th and last. The second internode bears two side branches and the third three. These main 

 branches are rudely alternate and curved .upward like candalabra. The lower one bears three 

 curved branchlets, and the third, one. All of the branches arise from calcareous internodes. 



The axis is rather faintly grooved, and seems to be hollow; but the specimen was too 

 small to justify dissection to ascertain this point. The polyps are biserial, alternate, and rather 

 distant, being almost 2 mm. apart. 



The individual calyces are club-shaped, directed outward basally, and curving upward, or 

 towards the branch termination, distally. A typical one measures 1.6 mm. in height and i mm. 



