224 



Family Isidae. 

 Ceratoisis ramosa, n. sp. 

 Plate VI L, figs. 3 and 4. Plate VIII., fig 12. 



Locality : Vasco de Gama Peak, N. 71 E., i8i miles. 230 

 fathoms. Stones. May 4, 1900. 



This specimen is a good deal broken, but considering its 

 •extremely fragile character it is sufficiently well preserved to 

 merit congratulation on its arrival. 



The base is missing, and the terminal branches have in many 

 places been lost, but I estimate its total height to have been 

 about 100 mm. The main stem is relatively thick (3 mm. in 

 diameter) and made up of calcareous intern odes 3-5 mm. in 

 length, alternating with homy nodes i mm. in length. The cal- 

 careous internodes give rise to the calcareous intemodes of the 

 branches, aiid the calcareous intemodes of the branches give 

 rise in a similar manner to the intemodes of the secondary 

 branches. The bronze colour of the nodes contrasts finely with 

 the ivory-white calcareous internodes as described by Verrill in C. 

 ornata. The branches arise very irregularly in all planes, and 

 the whole colony has the appearance of a low, dwarfed, finely 

 branched shrub. The smaller and terminal branches are very 

 slender, and have very long internodes with relatively short 

 nodes. The terminal branches are about 0.2 mm. in diameter, 

 with internodes 5 mm. long and pad-like nodes 0.4 mm. thick. 



Throughout the whole colony the coenenchym is extremely 

 thin. The main stem has the appearance of being quite naked, 

 but an extremely thin membrane bearing a few isolated zooids 

 can be seen on closer examination. The zooids are irregularly 

 scattered on the main stem, but are arranged on the branches at 

 intervals of 2 to 4 mm. apart. In some places on the terminal 

 branches three or four zooids may be close together, but they 

 are never so crowded as they are represented to be in Ceratoisis 

 grayii (4). The zooids with the tentacles folded over the crown 

 are about i mm. in height. The surface of the zooids and the 

 coenenchym is covered by plate-like spicules which in dried 

 specimens overlap in places, giving the surface a primnoid 

 appearance. 



The aboral side of the bases of the tentacles are usually pro- 

 tected by spicules of the shape given in fig. 4b., and remind one 

 of the opercular spicules of Primnoidae. Surrounding the neck 

 of the zooid there are curved spindle-shaped flat spicules about 

 9*4 mm. in length (Fig. 4c.). On other parts of the zooids and on 

 the general coenenchym the spicules are very irregular in size 

 and shape, but long flat spindles up to 0.6 mm. in length pre- 

 dominate. Irregular plates such as those drawn in Fig. 4a. 

 and Fig. 4d. are also found on the general coenenchym. 



