238 PROCEEDINGS OF THE NATIONAL MUSEUM vol. iob 



name. Conspicuous parenthesis-shaped chitinous rods enclose the 

 orifice. Zooecial orifice slightly salient. Operculum covers even the 

 orifice rim amply. Two small diagonal sclerites present on the oper-i 

 culum. No avicularia were seen. Description is based on only one 

 branch of a colony. 



Colony : Only a single small cylindrical fragment of the basal part 

 of a colony was available. It is about 1 mm. thick and 14 mm. long. 

 The ivory-colored sprig terminates in a tangle of chitinous radicle 

 fibers which arise from the calcareous zooecia near the base. The 

 areolation is hexagonal, but an occasional zooecium seems rhombic: 

 Zoids occur in a transverse series of four or five around the long axis 

 of the branch. 



Zooecia: The zooecia are longer than wide; their proximal ends are 

 well hidden beneath and between the side walls of the neighboring 

 proximal zoids. The visible surface area is shorter than the actuali 

 zooecial length as is true for all the species of this genus. The meas- 

 urements for this visible frontal surface of the zooecium are: lengthl 

 from 0.547 to 0.720 mm. (average 0.667 mm.); width 0.418 to 0.461:, 

 mm. (average 0.439 mm.). The zooecia are hexagonal but an occa-i 

 sional one is rhombic. Their distal arches or cornices are not sharply), 

 pointed but arched gently. The side walls or zooecial mural rims are( 

 raised, thin, and slanted from vertically to obliquely. In some places; 

 delicate lines or creases appear in the waUs, as if due to a series ofi 

 low tubercles arranged in rows or due to the irregularities in calcifica- 

 tion of the walls. A delicate, flat, parchmentlike membrane covers; 

 some of the zooecia, obscuring their skeletal characteristics. The( 

 cryptocyst in some zooecia is smooth, in others covered with small,! 

 irregular, somewhat closely placed tubercles, giving it a gently pebbled: 

 appearance. Scarcely noticeable tubercles sometimes are so lined upi 

 along the flaring side walls that the latter may have a faintly crinkled 

 or lined aspect. Other decorations of the zooecial frontal include the 

 very pronounced chitinous rods parenthesizing the orifice on the parch- 

 ment membrane, and the cryptocyst ridge. The latter varies in 

 completeness in the different zoids but eventually assumes a horse- 

 shoe shape or gives the impression of a garland around the orifice. 

 Its distal edges begin near the lateral walls of the orifice. 



Zooecial orifice: Because opercula are present the shape of the 

 orifice is somewhat obscured. The opercula appear very slightly 

 larger than the orifices and measure from 0.094 to 0.122 mm. (average ' 

 0.108 mm.) in length and from 0.122 to 0.144 mm. (average 0.137 mm.) I 

 in width. They are chitinous and have a faintly roughened or peb- • 

 bled appearance. None^was dissected away to reveal the orifice 

 or for detailed study because%f fear of damaging the lone sprig of 



