Anatomy of Gorgonid.e. 13^ 



are white and richly ciHated. They retain the germinal 

 vesicle even after they have reached a considerable size and 

 apparently have undergone complete segmentation, the dot 

 and vesicle being superficial in position. 



The ova are found as usual attached to the mesenteries, but 

 are generally quite low down toward the bottom of the calicle, 

 and not up near the gullet as is the case in PlcxaurcUa dichot- 

 oma. Fig. 7, shows an ovum with three germinal dots and 

 fig. 9, one in which the protoplasmic mass has shrunk away 

 from the vitelline membrane. Fig. 12, shows an ovum which 

 has developed an epiblast and hypoblast, but the germinal 

 vesicle and dot can still be seen. 



The pedicels bv which the ova are attached to the mesen- 

 teries are shorter, as a rule, than those of PlcxaHrcUa dichot- 

 oina. 



CcEXENCHYMA. Under this head may be mentioned a pe- 

 culiar propertv of this species which I have noticed in no 

 other. If a fresh zoanthodeme is allowed to die in sea-water, 

 the water will soon be colored a deep brownish black. 

 Whether this color is due to some chemical combination or 

 not I do not know. There is certainly no great amount of 

 black pigment in the zoanthodeme. There is, however, a 

 great deal of purple coloring matter in the mass of spicules 

 surrounding the axis cvlinder, and if any action of the salt- 

 water in connection with the decomposition of the zoantho- 

 deme could release this color and chantje it to black, there 

 appears to be a sufficient amount to produce the effect de- 

 scribed. 



Spicules. These are exceedinglv beautiful in this species 

 and are of two well marked forms. 



ist. Small echinato-clavate spicules represented in PI. VII, 

 figs. 2, 5, 10, 20, 22, 25. These form a dense mass immedi- 

 ately under the ectoderm of the zoanthodeme, being closely 

 interlocked by means of the peculiar plates and processes 

 which extend from their basal ends. This " cortical layer,'* 

 as Kent calls it, invests the entire crenenchvma and the exsert- 



