220 



describe any one form as typical. Ridley does not mention the 

 size of the spicules. Klunzmger (8), in his description of 

 Mopsea erythraea from the Red Sea, which Ridley places in this 

 genus, says the spicules are from 0'i6-'02 mm. in length and 

 ■03-0"o6 in breadth. The spicules I have measured in these 

 specimens vary in size up to about o"i5 mm. in length. 



An examination of a fragment of the type specimen of 

 Wrightella coccinea in the British Museum shows that the 

 spicules are much more crowded in the superficial coenenchym 

 than they are in the Cape specimens and the foliaceous clubs 

 larger ('2 mm. in length), and much more numerous. The dif- 

 ferences in this respect are so great that I was tempted to con- 

 stitute a new species for the Cape specimens, but when I exam- 

 ined a considerable number of specimens, and found that there 

 is a great variability in respect of the number and crowding 

 together of the spicules in the coenenchym and in the relative 

 number of clubs and foliaceous clubs, it appeared to me wiser to 

 include them in the species named by Gray. 



There is a difference of 30° latitude between Mossel Bay and 

 the Seychelles, and it is not surprising that the specimens of 

 Wrightella from the former locality should differ in this respect 

 from those found in the latter. There are other species of 

 Alcyonarians in which the tropical varieties exhibit larger and 

 more numerous spicules than the temperate varieties. 



The genus is characterised by its dwarf size. Wrightella 

 chrysanthus is 2j inches in height, and Wrightella (Mopsea) 

 erythraea is said to be 40-60 mm. in height by Klunzinger (8). 

 The average height of the Cape specimens is about 40 mm. 



The colour of the majority of specimens is red, but some are 

 orange or an intermediate colour between red and orange and 

 some pink. Ridley says that the verrucae of W. coccinea are 

 yellow. In this respect the Cape specimens differ from the 

 type, all the verrucae being red. The anthocodiae are white and 

 transparent, as described by Klunzinger for W. erythraea from 

 the Red Sea. 



I may here call attention to an erratum in my last paper on 

 the Cape Alcyonaria Wlien I examined Wrightella coccinea 

 I was strongly reminded of the specimen I described in that 

 paper as Primnoisis capensis (Studer), and I was led to a re- 

 examination of its structure. I am now convinced that it belongs 

 to this species. The pink colour and the somewhat stronger 

 habit may be associated with the fact that it was found in 20 

 fathoms of water, i.e., much deeper than the Mossel Bay speci- 

 mens, but the comparison of the spicule preparations revealed 

 so many general similarities of form that there can be no longer 

 doubt of their identity. The Blattkeule, which I overlooked in 

 my first examination, do occur, although they are not numerous. 



