8o 

 FAM. : MELITODIDAE. 



Melitodes dichotoma, Pallas. Plates L, II., 



AND VL, B. 



Three specimens were sent to me, which I believe belong 

 to the species called by Pallas Isis dichotoma, and amended 

 by Wright and Studer to Melitodes dichotoma. 



The following notes were attached : — 



" No. 2. — Yellow Alcyonarian (original colour) well pre- 

 " served, procured by large trawl in False Bay, lat. 34° 

 " 19' 15" S.; long. 18° 36' 30" E., over 8.35 p.m. — 

 *' 9.40 p.m. About half-a-dozen pieces procured, 27th Sep- 

 " tember, 1898. This is not nearly so abundant as No. i 

 " (Gorgonia flammea), only one other specimen having been 

 " got as yet, badly preserved. 



" No. 3. — Red specimen, got at the same time and place 

 '* and in same abundance ; badly preserved. 



" No. 5. — Specimen same as No. 2, but probably better 

 " preserved." 



It is interesting to note in this place that the red specimen 

 No. 3 turns out to be the best preserved specimen of an 

 Alcyonarian, that has been sent to me from abroad. It is 

 true that the polyps are not fully expanded, but the details of 

 the histology are almost perfect. 



The very striking difference in colour between the yellow 

 form Nos. 2 and 5 and the red form No. 3 suggest that we are 

 dealing with two distinct species, but the study of the hard 

 and soft parts shows that, except colour, there are no charac- 

 ters which separate the two forms (Plates I. and II.). 



It is well known that in the Alcyonarians the colour of the 

 spicules (and the colour of all preserved specimens is chiefly 

 due to the colour of the spicules) is a very uncertain and 

 variable character. Von Koch (3) gives a very beautiful 

 example of this in Muricea chamaeleon, in which yellow and 

 red varieties occur, and one specimen which he figures is 

 partly yellow and partly red. 



The fact that the yellow and red varieties of Melitodes 

 dichotoma were taken in the trawl at the same time and place 

 only confirms the opinion gained by the study of anatomy 

 that they are not distinct species. It is quite probable that 



