REPORT ON ACTINIARIA. 243 



given bv Haddon and Shackleton 1 '91 and '91 bis), and con- 

 sequently refer this form, which according to Erdmann's 

 classification 1 "S5 | would be regarded as a Corticifera. to the 

 genus Palythoa. 



The colonies form compact masses, with a thickness of 

 about 1-1.5 cm., the individual polyps measuring on an aver- 

 age about 0.7 cm. in diameter. As in other members of the 

 genus thev are imbedded in ccenenchyme throughout the 

 greater portion of their length, only the upper part of each 

 individual beino- free, though it is to be noted that even the 

 most contracted individuals project somewhat above the gen- 

 eral level of the ccenenchyme. Many of the individuals were, 

 however, onlv partially contracted, the mouth and a portion 

 of the disk being frequently visible, but in all cases the ten- 

 tacles were curled in beneath the margin so that thev could 

 not be counted. The general color of the preserved colonies 

 was yellowish sandy, the color deepening towards the bases 

 of the tentacles to what is almost orange. The disk is appar- 

 ently of a lighter shade than the column and a considerable 

 quantity of black pigment, in the form of granules, occurs in 

 the endoderm of the mesenteries especially towards their inner 

 ends below the level of the stomatodaeum. and also in the 

 lacunar spaces of the lower portion of the column wall and in 

 the basal lacunae of the mesenteries. As a result of the 

 presence of this pigment the lower portions of the colonies 

 have a greyish black color, very distinctly seen when a por- 

 tion of a colony is cut away or when the base of the colony is 

 examined. 



The mesoglcea is throughout thickly studded with foreign 

 particles, mostly irregular fragments of carbonate of lime, 

 though foraminiferous shells and sponge spicules also occur. 

 In sections through decalcified specimens the column wall has 

 a fenestrated appearance owing to the imbedded particles hav- 

 ing been dissolved out 1 PL in. Fig. 6). Of the ectoderm 

 little can be said, as the preservation of the material was bv 

 no means what was to be desired, but apparently it was not 

 divided into compartments by lamella? of mesoglcea as in 

 IV— 3 X a 



