Coloration of Echinus angulosus, A. Agass. 191 



wide distribution of tliis species. Regarding the colour, 

 Agassiz states that the longer and more slender spines gene- 

 rally have violet tips, and that the shafts have all shades 

 between violet and the lightest yellow. Meissner has 

 recorded Echinus angulosus from Cape Town, and writes 

 that the colour of the spines of his specimens differed from 

 those described by Agassiz in that they were a uniform brown 

 throughout, while those of Agassiz's forms had coloured tips. 

 Meissner, however, states that he was unable to state whether 

 this was a colour variation, as he had no available notes on 

 the coloration of living forms. 



The specimens of Echinus angulosus, the colour variation 

 of which I noted, were mainly collected from three littoral 

 localities in False Bay and Table Bay ; but I also examined 

 specimens taken by the trawl in deeper water, viz. at a depth 

 of 20 fathoms. Echinus angulosus occurs in great numbers 

 in the rock-pools at low tides, and the species is of some 

 slight economic value, as it is used as food by some of the 

 numerous nationalities represented in Cape Colony. The 

 species lends a bright colour to the pools in which it is 

 found and can be noticed at some distance. 



At Sea Point, to the west of Cape Town, the following 

 varieties of colours among the specimens -were noted : — 

 Purple, 43 specimens ; red, 7 specimens; green, 15 speci- 

 mens; grey, 38 specimens ; intermediate between purple and 

 grey, 2 specimens; intermediate between green and purple, 

 3 specimens. 



The species was seen to be sexually mature in May, and 

 on examination the females were found to be purple, red, 

 green, grey, intermediate between grey and purple, and 

 intermediate betw T een green and purple in colour. The males 

 were purple or grey in colour. The females were more 

 abundant than the males, only 10 to 20 per cent, being of 

 the latter sex. 



From the first locality at which examples were collected 

 and examined it is thus evident that the sex of the specimens 

 could not be identified by their colour. 



On another occasion at Sea Point, the proportion of colours 

 was as follows : — Purple, 8 ; green, 6 ; grey, 4 ; red, 1 ; 

 intermediate between grey and purple, 1 ; intermediate 

 between grey and green, 1 ; intermediate between grey and 

 brown, 1. 



In the rock-pools at St. James's, in the vicinity of the 

 Marine Biological Station, of seventeen specimens examined 

 having a predominating red colour twelve were females and 

 five males. The distribution of the colour of theso specimens 



