HiCKSON —Notes on a Small Collection of Sydrocorallince. 509 



in the structure of their soft parts from the type that has been 

 ■described and figured by Moseley. It is possible, however, that 

 when we have more knowledge of the gonophores of the different , 

 species, specific differences may be found, but at present the ova 

 and sperm sacks have been seen only in the two species, M. 

 Murrayi, and M. 'plicata. 



In view of the interesting facts that may come to light by the 

 investigation of the anatomy of this interesting form, I may be 

 allowed to repeat my request that all naturalists who have an 

 opportunity of collecting specimens on the coral reefs of any part 

 •of the tropical world, will take care to preserve some branches of 

 Millepora, in strong alcohol, and send them to me at Cambridge. 

 I am more particularly anxious to obtain specimens from 

 Bermuda and the West Indies, and I may add that the value of 

 the specimens will be greatly increased if careful notes are made, 

 on labels attached to the specimens, of the time of year that they 

 were collected. 



EXPLANATION OF PLATES. 



Plate XYIII. 



^jg, 1. — Female stock of JDistichopora vtolacea, drawn and coloured from 

 a spirit specimen. Natural size. 



Fig. 2. — A small portion of the same enlarged to show the female 

 gonophores {ffp.), arranged in a cluster on the flahellar surface 

 of a secondary branch. 



I'iG. 3.— A portion of a male stock (x 2), showing the male gonophores 

 lying in a cluster on the flahellar surface of a secondary branch. 

 The male gonophores are not so large nor so prominent as the 

 female gonophores, and in dried specimens are scarcely 

 visible. 



]Fi(j. 4 _A portion of a small sterile stock of a bright yellow colour. 

 (x 2). 



