mm, in height and 1 . ; mm. in diameter at the base. 1 hey are closely approximated on the 

 disi more distant, although still rather closely emplanted on the 



proxim; margin is surrounded by 8 lul.es which form an 8-rayed figure when 



Mi.- calyx walls are filled with densely tuberculate spindles which are 



ital on basal parts and tend to 1"- vertical on distal parts, especially in the mar- 



In the coenenchyma the spicules are longitudinal as a rule. I 'he polyps are com- 



I in retraction li<- well below the infolded lobes of the calyx margin. The 



ry wc ik. s evident. The tentacles are covered on their dorsal surfaces by 



small tuberculate spindles which are longitudinal on the distal parts and tend to an en chevron 



nent «>n the proximal parts. 



The coenenchyma is moderately thin. A cross section of the stem shows inconspicuous 

 water-vascular canals and a corneous axis which is slightly flattened. 



Spicules. Stemt, densely tul .erculate spindles of moderate si/e, with the tubercles not 

 arr in distinct whorls, are the characteristic form of this species. Those in the tentacles 



smaller and more slender. Rarely a clubshaped form is scen. 



lor. The colony, in alcohol, is a light brown with a faint reddish cast in places. 



G mis Platycaulus Wright and Studer. 



Platycaulus Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 148. 



The original definition of this genus is as follows: 



Colony branched, the branches in one plane, anastomosing. The axis is horny, flattened, 



with a calcareous «-entre and calcareous particles interspersed amid the horny layers; the nutriënt 



..mals surrounding the central axis almost as in Plexaura. Polyps prominent, on the sides ot 



stem and branches, retractile within verrucae. Coenenchyma moderate, like shagreen. Spicules 



straight and curved spiny spindles and stellate forms". 



The type, and hitherto the only known species of the genus Platycaulus is Platycaulus 

 danielsseni Wright and Studer. 



1. Platycaulus sibogee new species. (Plate II, figs. 2, ia-. Plate III. fig. 1 



it. :i;. Saleyer Anchorage and surroundings. Up to 56 meters. 



Colony flabellate, not reticulate, although there are a few anastomoses, loose and flabbj 



in texture, 35 cm. high. il upright sterns spring from a single encrusting base. The largest 



has its main stem and many of the branches and twigs flattened. The stem forks 



from its base into two unequal branches the largest of which is 6.5 mm. 5 mm. in 



\ft'-r giving off several small lateral branches it again forks, 11 cm. trom its 1 



iltant branchlets again give off irregularly disposed lateral branchlets at intervals 



B anches of the 6 >metimes attained. In a few cases the branches 



an but not often. The ultimate twigs are flattened, being about 2 mm. by 1 mm. in 



raly pinnate in arrangement. The calyces are usually lateral in position, 



