70 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.43. 



ones in a given row being but 3 mm. The calyces are distant and 

 usually regularly alternate, averaging about 2 mm. apart. They 

 are considerably curved, with large distal and slender proximal 

 parts, as if borne on pedicels, they are almost never in pairs and 

 are usually regularly alternate with the mouths opening upward. 

 A typical calyx is 1.5 mm. high to margin. The scales are all thin 

 and delicate, the circumopercular ones with long sharp spines, 

 those on the adcauline scales being very short or absent. The 

 edges of the calyx scales are minutely ctenate. The circumopercular 

 spines are 1 mm. long and very slender. Owing to the delicacy 

 of the scales it is hard to determine the number in the several rows, 

 but they are more numerous than usual, probably 8 or 9 in the 

 abaxial rows and 6 or 7 in the laterals, and apparently 4 in the 

 adaxials. 



The operculum is low, conical, composed of such exceedingly 

 delicate scales that they are seen with difficulty by reflected light. 

 They are flat, triangular. The tentacles of the polyps are partly 

 protruded. 



The scales are the most delicate of any that I have seen in this 

 family, but are of the common type found in Thouarella, Caligorgia, 

 etc. 



Color: The axis of the stem is golden-green. The general color 

 of the colony is almost white. 



Localities. — Station 5079; Omai Saki Light, N. 29° E., 24 miles; 

 475-505 fathoms. Station 5080; Omai Saki Light, N. 23.5° E., 28 

 miles; 505 fathoms (type). 



Type-specimen. — Cat. No. 30097, U.S.N.M. 



The alternate disposition of the calyces and the number and 

 extreme delicacy of the body scales are characteristic features of 

 this species. 



Genus PRIMNODENDRON, new genus. 



Colony growing in dense flabellate tufts, each branch giving off 

 a series of branchlets from all sides and each branchlet dividing 

 into a dense tuft of terminal twigs which together form a closely 

 compacted mass of twig terminations, most of which are directed 

 anteriorly, fornung a peculiar matted surface. Calyces in indistinct 

 rows, being neither in pairs nor in whorls. Individual calyces much 

 like those of PlumareUa. 



Primnodendron differs from PlumareUa in bearing secondary 

 branchings from the terminal twigs, and from Thouarella in having 

 the calyces arranged neither in pairs nor in whorls. 



Type of the genus. — Primnodendron superbum, new species. 



