CORALS FROM SOUTH AFRICA. 883 



Localities, e^c— P.P. 13345. Off Cape Morgan, N.N.W. 7 

 miles. Depth, 52 fathoms. By dredge. Nature of bottom, rocks, 

 sand, and shells. Date, August 12, 1901. 



P. F. 858. Off and east of Cape Morgan. Depth, 36 fathoms. 

 By dredge. Nature of bottom, stones. Date, January 12, 1899. 



Vei'rill's diagnosis of the genus Psam7nogorgia is as follows : — • 

 " Corallum dichotomous or subpinnate, with round branches. 

 Axis horn-like, Coei:ienchyma moderately thick, the surface finely 

 granulated with small rough spicula. Cells scattered, sometimes 

 flat, more frequently raised in the form of rounded verrucfe. 

 Polyps with rather large, elongated, slender warty spindles at the 

 bases of the tentacles. Spicula of the coenenchyma mostly short, 

 thick, and very rough, warty spindles and rough, warty clubs of 

 moderate size." 



Eleven other species of Psammogorgia have been described. 



EuPLEXAURA MEDIA, sp. n. (Plate XLIV. figs. 2 a-c.) 



The colour of the colony is bright red, with white polyps. A 

 large part of the colony is concealed beneath a thick growth of 

 Hydroids, and thus the exact dimensions of the specimen are 

 rather uncertain. It Avas probably about 25 cm. in length. 



In the lower part of the colony the axis is much flattened, but 

 towards the apex it becomes rounded. The large axis near the 

 base of the colony is 3*5 mm. in one diameter and 1*6 mm. in the 

 narrow diameter. The axis is very small towards the a,pex of the 

 colony, and is surrounded by the canals in a circular manner. 

 The axis is hollow, and has the structure described by Wright and 

 Studer for the genus Ev,plexan,ra. 



The base of the colony is missing. The branches are all in one 

 plane and vary in diameter at different parts of their length. 

 They are thick near the base, narrower medianly, and expand 

 again near the apex. 



The polyps are arranged in an irregular spiral round the 

 branches. The polyps are in many cases fairly well extended, but 

 others are retracted and appear only as minute pores on the 

 surface of the coenenchyma. These pores vary in shape, some are 

 circular or oval, othei^s are slit-like and elongated in the direction 

 of the long axis of the branch. The pores are from '3 to -5 mm. 

 in diameter. A well-expanded polyp is about 1*2 mm. in length 

 and '5 mm. in diameter. 



Each tentacle has about ten pairs of pinnules. The spicules are 

 situated at the bases of the tentacles and extend in a distal 

 direction. There is, firstly, a series of spicules on the polyp sur- 

 face in a line with the tentacles, and, secondly, another series 

 placed intermediate to the first. The second series has not so 

 many spicules as the first. The spicules in each of these sei'ies are 

 not arranged in a very regular manner. 



The coenenchyma is dense and granular. The spicules are 

 arranged in a very dense layer in the cortex, but thei-e are fewer 

 towards the axis. 



