1 1 



Colony branched, the stem and branches having well differentiated cortical and nuclear 

 portions, the latter forming an axis which is penetrated by large water-vascular canals. Polyps 

 only partially retractile. Stem cylindrical. 



STUDER (1887) considers this genus to be closely related to Solenocaulon and defines it 

 as shown in the following translation : 



"But here the stem has a more cylindrical form and the nuclear mass withdraws more 

 to the axis of the colony although it is always excentric and the polyps, as in the previous 

 genus, are situated mainly on one side of the stem and branches". 



This definition is repeated by WRIGHT and STUDER in their Challenger Report (1888) 

 and is adopted for the present work. 



The type and, up to the present time, the only known species of the genus is Semperina 

 rubra Kolliker. One new species is added in the present work. 



i . Semperina rubra Kolliker. 



Semperina rubra Kolliker. Beitrage zur Kenntniss der Polypen, 1870, p. 9. 



Stat. 258. Tual Anchorage, Kei Islands. 22 meters. Lithothamnion, sand and coral. 



Colony incomplete, straggling in habit, 13.5 cm. in height. The main stem is hollowed, 

 probably by some parasite or pathological condition, and probably flattened naturally, 2.3 cm. 

 long to first forking and i cm. in greatest diameter. One of the main branches is simple, 

 irregularly flattened, (a cross section near its base being 7 mm. X 4 mm.) and somewhat 

 spirally twisted. The other main branch bears a number of very irregular mostly lateral 

 branchlets projecting in an erratic manner from the main branch. One of the apparent branchlets 

 is really a branchlet from a missing part of the colony which has anastomosed with the part 

 secured. All of the branchlets are simple, most of them round in section and clavate at the 

 ends. The calyces are distributed on three sides of the branches, with a marked tendency to 

 aggregate in groups or clumps on one face of the branch or on the ends of the branchlets. 



The individual calyces are almost entirely included in ihe ccenenchyma and appear as 

 very low verrucae about 2 mm. in diameter and with scarcely appreciable height. The polyps 

 seem to be non-retractile, at least all are expanded in the specimen studied. They are very 

 heavily spiculated, there being an unusually broad and heavy collaret of encrusting spindles 

 which assume an en chevron arrangement just below the tentacle bases. The proximal part 

 of the tentacles are covered with longitudinal spindles in several rows, and the distal parts 

 are completely covered dorsally with spindles arranged in two series placed en chevron and 

 reaching to the bases of the pinnules. 



A cross section of a branch shows a rather thin ccenenchyma in which is embedded a 

 regular circlet of water-vascular canals around the periphery of the axis. The axis is flattened 

 and penetrated by a number of conspicuous water-vascular canals. 



Spicules. These are exceedingly varied in form, but most of them are modifications 

 of the simple spindle. The spindle forms range from excessively slender rods with smooth 



