88 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.43. 



filled with small round disks with darker centers and lighter edges. 

 The polyps are retractile, with well-marked collarets consisting of 

 usually three wavy bands of spicules, the convexities lying at the 

 tentacle bases. The operculum is strong, composed of the usual three 

 spindles forming an acute-angled triangle reenforced by other similar 

 spindles, some of wliich lie along the dorsal surfaces of the tentacles. 



Spicules: These are of the characteristic "collar-button" type of 

 this genus, the central stalk or pillar between the two expanded por- 

 tions being rather longer than in other species, and the edges of the 

 lower, or larger, disks being frilled. There are also a few slender, 

 tuberculate, and often curved spindles. 



Locality. — Station 4935; Sata Misaki Light, N. 58° E., 4,5 miles; 

 103 fathoms. 



General distribution. — Type-locality, Ceylon Seas; also reported 

 from the Dutch East Indies (Nutting). 



Family PLEXAURID.^:. 



Axis composed of lime salts and corneous matter, not in regular 

 segments; calyces often included, found on all sides of the stem and 

 branches; spicules various, often club-shaped; coenenchyma tliick, 

 with a regular series of large primary water-vascular canals arranged 

 around the axis cylinder. 



Genus EUPLEXAURA Verrill (emended). 



Axis consisting of a horny core surrounded by a thick cylinder of 

 horny material extensively impregnated with calcareous matter. 

 Calyces rather large for this family. Spicules mostly short, warty 

 spindles and small crosses. 



EUPLEXAURA PINNATA Wright and Studer. 



Euplexaura pinnata Wright and Studer, Challenger Reports, the Alcyonaria, 

 1889, p. 144. 



Colony subflabellate, straggling in habit. Stem round, 4 mm. 

 thick, unbranched for 4.8 cm. of its length. It then gives off a pair 

 of opposite branches which attain branchings of the fourth order. 

 Above tliis a number of lateral branches are given off, some opposite, 

 some subopposite and some alternate ; all rather distant, the distance 

 varying from 1 cm. to 2.3 cm. The branches are slightly clavate at 

 their ends and have a diameter of about 2.5 mm. The calyces are 

 fairly regularly distributed on all sides of the stem and branches and 

 are completely included in the coenenchyma, their oval openings alone 

 indicating their presence aside from a slight tumidity around the 

 margins. They are about 1.8 mm. from center to center. The 

 polyps are completely rectractile. The tentacles bear longitudinally 

 disposed curved spindles. 



