4 The Philippine Journal of Science 1915 



may consist of a main stem, from which arise throughout its 

 length numerous long branches, or it may consist of a number 

 of stems arising from or near the base. The slender lateral and 

 terminal lobes which are borne on the primary or secondary 

 divisions of the main branches are cone-shaped in contracted 

 specimens and nearly cylindrical in expanded colonies. They 

 vary greatly in size and arrangement, reaching a length of 

 about 20 millimeters in expanded specimens. The polyps are 

 arranged singly or in little groups on the lobes and are not 

 crowded in expanded specimens. They are from 0.6 to 1 mil- 

 limeter in length and from 0.5 to 0.7 millimeter in diameter. 

 The short thick tentacles make a right angle with the oral sur- 

 face in expanded polyps and give them a flowerlike appearance. 

 The tentacles average 0.4 millimeter in length and 0.15 milli- 

 meter in width and bear on either side from 6 to 8 short, thick, 



Fig. 1. Spicules from the stem cortex of Litho- 

 phytum philippinensis sp. nov. X 112.5. 



rounded pinnules. The contracted polyps are club-shaped, and 

 the tentacles are folded in over the edges of the oral surface, 

 leaving a hollow in the center. 



The spicules of the stem cortex are straight or slightly curved, 

 opaque white spindles covered with large, blunt, smooth or tuber- 

 culated projections flattened in the line of the short axis of the 

 spicule. These spicules form a scattered layer on the base and 

 the stem, being absent in the branch cortex and in the polyps. 

 They show a dark central axis and are from 0.2 to 0.45 milli- 

 meter in length and from 0.025 to 004 millimeter in diameter. 

 Scattered among these spindles are smaller, smoother, rod-shaped 

 spicules with a few conical projections. The ends of all the 

 spicules are more or less flattened and divided and receive 

 branches from the central axis. 



The canals are numerous with very thin walls containing few, 

 if any, spicules. They radiate from the center where their walls 

 are fused and thickened to form a small central axis containing 



