KEPORT ON THE XENIIDAE COLLECTED BY DR WILLEY. 



519 



•004 mm. in thickness. They are white or slightly bluish-white by reflected light but 

 light reddish-brown by transmitted light. There are comparatively few spicules in the 

 stem but they are more numerous in the body of the polyp, especially towards its 

 distal end around the bases of the tentacles. They are abundant in the tentacles 

 and very numerous on the outer face of the jDinnules, where they are almost in 

 contact with each other. (See Figs. 5 and 6.) 



All the stems of the specimens are a very pale yellowish -green colour, but the 

 polyps are whitish with a pale bluish bloom, due to the very numerous spicules which 

 they contain. 



Three of the colonies have been examined for sexual products and all proved to 

 be males. On the mesenteries of many of the larger polyps sperm sacs are present 

 in considerable numbers, in some cases they are so numerous that they almost fill 

 up the cavity of the coelenteron in which they are contained. The largest sperm sacs 

 are about -32 mm. in diameter and contain almost ripe spermatozoa. (The ripe sperm 

 sacs of X. Hicksoni measure -35 mm. in diameter.) The sperm sacs are found only in 

 those portions of the coelentera contained in the upper o mm. of the stem. (See Fig. 7.) 

 From each of the colonies two or three of the largest polyps were removed, stained and 

 cleared. The stomodaeum is very uniform in length throughout. Its length averages as 

 nearly as pqssible 1 mm. In some of the smaller polyps (the body of which is only 

 about 3 mm. long) the stomodaeum is "8 mm. long, while in the largest polyps (the body 

 of which is about 5 mm. long) it is about 1-2 mm. in length. In one of the most 

 favourable specimens, cells very similar to the goblet cells to which reference has been 

 made above may be seen in the ventral and lateral walls of the stomodaeum. 



Appended are the details of the various colonies : — • 



The colonics from Talili Bay have a very convex polyp-bearing surface. Their 

 polyps are slightly smaller than those of the specimens from Lifu, the bodies of the 



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