2O 



i. Titanidium friabilis new species. (Plate III, figs, i, iff; Plate XI, fig. 6). 

 Stat. 304. Lamakera, Solor Island. 16 meters. Coral and sand. 



Specimen dried and exceedingly brittle, as if made of soft chalk, 31 cm. in height. 



Two large stems are coalesced shortly above their bases and are closely adherent for 

 8.3 cm. These and all of the branches are round in section, the larger stem being 1.5 cm. in 

 diameter. One of these stems is broken off before branching and the other forms the remainder 

 of the specimen. The stem curves strongly, becoming almost horizontal for .5 cm., after which 

 it suddenly breaks up into a dense tuft of branches and branchlets which form a dense clump 

 or cluster of numerous ultimate twigs. The stem also gives off a single straight branch where 

 it separates from the other stem. This branch forks and one of the resultant branchlets subdivides 

 several times and adds to the clump forming the distal end of the colony. Branchings of the 

 5 th order are sometimes attained. The ultimate branchlets are not noticeably turgid at their 

 ends and are usually about 4 mm. in diameter. The polyps are distributed on all sides of the 

 branches much as in Plexaura, and the calyces are entirely included. 



The individual calyces are indicated externally by their apertures alone. These are oval 

 or slit-like according to the state of contraction of the polyps, and the slits are cut at various 

 angles to the axis of the branch and are more abundant on the terminal than on the proximal 

 parts of the colony. On the twigs they average a little more than i mm. apart and in places 

 show a tendency to a linear arrangement. The character of the polyps can not be ascertained 

 from the type, which is a dried specimen. 



The axis is not well defined and is more friable than any other of this family that I 

 have seen. The ccenenchyma is rather thin and the water-vascular canals form an irregular 

 circlet around the axis. 



Spicules. The spicules of the ccenenchyma are very densely tuberculate and short, 

 sometimes oval, spindles, the tubercles usually entirely concealing the actual surface. While 

 such forms as KOLLIKER figures a for Titanidium suberosum can be found, they are not nearly 

 so abundant as these densely and coarsely tuberculate spindles. In the axis there are a few 

 slender forms with thorny verrucae, approaching the characteristic spicules of the axis of Soleno- 

 caulon; but these are greatly outnumbered by the coarsely tuberculate spindles described above. 

 Occasionally more slender spindles are seen, which may be younger spicules. 



Color. The colony (dried) is creamy white. When immersed in alcohol it assumes a 

 decidedly yellow color. 



1 Icones Histiologies, II, 2, plate XIX, figs. 19,' 20 and 22. 



