13 



calyces closing over them, but showing an eight-rayed margin. The polyps are very small, and 

 it is difficult to make out their characters of spiculation on account of the intimate cohesion 

 of the polyp and calyx walls. It seems, however, that there are a few spindles longitudinally 

 arranged on the walls and tentacles. 



A cross section of a branch shows the ordinary features of this family, except the structure 

 of the axis cylinder. This has a very decided intercalation of lime salts, the axis appearing to 

 be composed of fibres between which are deposited the calcareous particles in such quantities 

 that the axis boils violently when immersed in dilute acid. The watervascular canals seem fewer 

 and more widely separated than is common in the Plexauridse. 



Spicules. These are all densely tuberculated spindles which are so short as to become 

 oval in outline, and to resemble the disk-like forms of some species of Placogorgia. There is 

 little variation, except in size, probably due to age. 



Color. The colony is scarlet throughout, except the polyps, which still show a yellowish 

 color in alcohol and were probably bright yellow in life. 



2. Euplexaura mollis new species. (Plate III, figs. 4, 40; Plate IV, fig. 8). 

 Stat. 299. io52'.4S., 123!'. lE. Cyrus Bay, Rotti Island. 34 meters. 



Colony incomplete, flabellate and reticulate. The proximal part is missing, the specimen 

 being 27 cm. in height and 15 cm. broad. The main stem, or branch, forks about 3 cm. from 

 its proximal end, and behind this forking a thick stump of a branch is directed backward and 

 a little downward. One branch of the fork is cut off 6.5 cm. from its base and is connected 

 by heavy anastomoses with the other branch. This latter forms the main part of the colony, a 

 central stem proceeding nearly to the periphery where it is dissipated in the reticulation. The 

 ultimate twigs are slender and but little over i mm. in diameter. The calyces are distributed 

 on all sides of the branches, their openings being about i mm. apart. 



The individual calyces are almost entirely included in the ccenenchyma, and show externally 

 as low, dome-shaped verrucae with small round apertures, in the dried specimen. The polyps 

 are small and retracted so that their infolded tentacles are almost on a level with the calyx 

 margin in alcoholic specimen. The margin is lined with an eight-lobed membrane caused by the 

 infolding of the cesophageal region of the polyp. The infolded tentacles are provided with a 

 pseudo-operculum much like that of the Muriceidae. 



A cross section of a branch shows a moderately thick ccenenchyma with two layers of 

 spicules imperfectly divided by the series of watervascular canals, but not showing two distinct 

 kinds of spicules. The axis cylinder is full of intercalated particles of lime salts, as in the last 

 species, and effervesces violently in weak acid solution. 



Spicules. The spicules of this species are all small, even minute, in comparison with 

 others of the family. The most common form is a small terete spindle with relatively large tubercles 

 arranged in definite whorls. There are also minute globular forms, crosses and dumb-bells. 



