occurring in the English Channel. • 481 



I would now indicate that the points stated above, by 

 "which von Koch seeks to distinguish Gorgonia verrucosa 

 from Gorgonia cavolhii, are not sufficiently constant in either 

 variety to enable one to hold this position. 



I have already alluded to the colour, and pointed out that 

 the red coloration of Gorgonia cavolini is unstable. In 

 regard to size, the relative size of the red and white form is 

 so variable that it appears to me that no definite character 

 can be deduced from tiiis point. 



Specific characters are derived by some authors from, the 

 mode of branching, but von Koch's most important contrast 

 in this respect — namely, the branching in Gorgonia cavolini in 

 one plane but not so in Gorgonia verrucosa — does not hold 

 strictly true for many specimens of either form which I have 

 examined. Further, I find the disposition of the branches, 

 their relative thickness to the stem, so variable in both the 

 white and the red variety that 1 cannot attach specific 

 importance to these points. 



liegarding the mode of occurrence of the polyps on the 

 twigs, I have been unable to find in a number of the red 

 forms, Gorgonia cavolini, a regular arrangement in rows. 



In the older colonies of Gorgonia verrucosa one frequently 

 finds that the majority of the polyps have a 5-lobed calyx, 

 and, on the other hand, one occasionally observes an 8-lobed 

 calyx in Gorgonia cavolini. Von Koch notes and figures in 

 another part of his monograph that there is variability in 

 regard to this point. I believe that the presence of eight 

 lobes in the calyx is only a temporary stage. 



It seems true that yellow cells are, as a rule, present in the 

 tentacles of the polyps of Gorgonia verrucosa ; but, on the 

 other hand, I am unable to confirm Koch's statement that 

 these yellow cells do not occur in the tentacles of Gorgonia 

 cavolii i» 



In his tables for the identification of the Gorgonacese of 

 the Gulf of Naples, von Koch gives as a common character 

 of Gorgonia verrucosa and Gorgonia cavolini that the polyps 

 are without spicules. In another part of his monograph he 

 writes of the presence of a number of needle-like spicules in 

 the young developing polyps, and of these being later reduced 

 in number in slightly older polyps to seven or eight for each 

 tentacle, but that these spicules are absent in tiie polyps of 

 the trunk. In both forms I find seven needle-like spicules 

 at the base of each tentacle in the polyps of the trunk. 



My reasons for regarding Gorgonia verrucosa and Gorgonia 

 cavolini as the same species are as follows : — 



The " habitus " of the two forms is, on the whole, the same. 

 The form, size, and distribution of the spicules is similar. 



