10 



This genus has much in common with the genus Eunicella Verrill, especially in the 

 form of the spicules. 



1. Plexauroides prcelonga (Ridley). 



Plexaura prcelonga Ridley. Report on the Zoological Collections of H. M.S. Alert, 1884, p. 339. 

 Plexauroides pralonga Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 138. 

 Plexaura pr&longa, var. elongata Thomson and Henderson. Ceylon Pearl Oyster Fisheries 

 Report, Alcyonaria, 1905, p. 305. 



Stat. 273. Anchorage off Pulu Jedan, East coast of Aru Islands. (Pearl Banks). 13 meters. 



Colony (dried) flabellate in form, 62 cm. in height and about 20 cm. in spread. The 

 main stem gives off a large branch 9 cm. from its base, and this bears several lateral branches 

 which are usually simple and attain a length of as much as 24 cm. The remainder of the 

 colony consists of the continuation of the main stem and its branches. These latter are roughly 

 alternate in position and tend to divide dichotomously until branches of the third order are 

 produced. The terminal twigs are very long and slender. The diameter of the main stem 

 is 9 mm., and of the branches about 3 mm. The calyces are entirely inserted, and are so 

 completely immersed that only their openings are seen. They are evenly distributed on all 

 sides of the branches, their mouths being about i mm. apart. 



Nothing but the openings of the individual calyces are to be seen in the dried specimens. 

 These are oval and less than i mm. in their longer diameter. The polyps could not be seen 

 in the specimens at hand. 



A cross section of a branch shows a very thick ccenenchyma with a superficial layer of 

 "Blattkeulen" standing at right angles to the surface, and an inner layer of colorless cruciform 

 or stellate spicules. The watervascular canals are large and conspicuous. The axis cylinder has 

 a white, noncalcareous core. 



Spicules. These are mainly typical "Blattkeulen" with a branched and densely tuber- 

 culate basal portion and a distal, disk-like comparatively smooth part. This latter portion is 

 often inflated in appearance and approaches very closely the Echinogorgia type, as pointed out 

 by STUDER in his study of Plexauroides lenzii 1 besides these, which are by far the most 

 numerous, there are cruciform and stellate spicules of much smaller size. 



Color. The colony is bright crimson. The axis is black, fading distally to a light 

 greenish brown. The spicules are bright red. 



General distribution. The type was secured in Torres Strait. The Challenger found 

 it off Cape York at a depth of 8 fathoms. It was secured also from the Pearl Banks of Ceylon. 



This is a very beautiful and well 'marked species. 



2. Plexauroides lenzii Studer. 



Plexauroides lenzii Studer. Alcyonarien aus der Sammlung des Naturh. Museums in Liibeck, 

 1894, p. 114. 



Alcyonarien aus der Sammlung des Naturh. Museums in Liibeck, 1894, p. 114. 



