Anatomy of Gorgomd^. 143 



haps, of Briarcuni. The branches are round, and about the 

 size of those of the preceding species. 



The color is a dark brown, considerably darker than those 

 heretofore described. Some specimens that I saw, however, 

 were of a light greyish color, but in ever}' other respect they 

 appear to be identical with Ennicea tourncforti to which I 

 refer them. 



CiiUclcs, exserted, thickly implanted over the surface of 

 the zoanthodeme (PL VIII, fig. i). Each calicle bends some- 

 what abruptly upward a little beyond the middle, so that 

 part of its exterior wall is vertical and the calicle opens up- 

 ward (PI. VIII, fig. 2). The opening of the calicle is not fur- 

 nished with movable lips as in the preceding species, and is 

 probably never closed, although, of course, it may be filled by 

 the body of the polyp. The top of the calicle is lobed, the 

 lobes corresponding in a general way to the spaces between 

 the tentacles of the polyps. One lobe, usually the outer one 

 is greatly enlarged so that it forms a prominent projection 

 extending upward, affording a useful protection to the polyp. 



Very young polyps in this and the preceding species of 

 Etmicea^ have no distinct calicles but make their appearance 

 on the surface of a branch between the older calicles. It 

 appears that the calicle grows ^ari passu with the young 

 polyp, as was to be expected. 



It is interesting in this connection to notice that the new 

 polyps in Tiibipora appear at first without any trace of the 

 tube so characteristic of this coral, taking their origin from 

 the platforms around the mouths of older polyps, and build up 

 their tubes of agglomerated spicules as they grow.' 



Polyps non-retractile, or at least only partially retractile, 

 not being able to withdraw entirely within the zoanthodeme. 

 When fully expanded they stand considerably above the cali- 

 cles, even above the greatly enlarged calicular lobe. When 

 retracted, or perhaps more properly contracted, they occupy 

 about the position figured in PI. VIII, fig. 2. The level of the 



I Duncan — "On the Structure and Relations of Tubipora." 



