The Actiniae of tlie Plate CoUection. 237 



while the Statements as to the latter read as follows: "Mauerblatt 

 g-rüngrau mit Läng'sreilien von braunrothen Warzen. Fühler schwarz- 

 g-rau, manchmal weiss gesprenkelt. Mimdscheibe tief rothbraim." 

 In the preserved condition the coloration varies somewhat and is 

 due to the black pig-ment contained in the endoderm, all traces of 

 the reddish color having'i disappeared. In the specimens from Puerto 

 Montt tliis endodermal pigment is abundantlj- developed and their 

 color is a uniform dingy grey-brown, the centre of each Verruca 

 being of a clearer brown and the tentacles almost black. The 

 specimens from Tumbes are either entirely colorless or the upper 

 part of the column is dingy dark slate colored, and the Calbuco 

 specimens are quite colorless , except where the ectoderm has been 

 rubbed away the endodermal pigment then showing through and 

 giving a dark slate color. 



Structure. The mesogioea of the column wall is in general 

 thinner than the ectoderm, and bears on its inner surface low pro- 

 cesses for the support of the endodermal musculature. In the region 

 of each Verruca the column wall shows a slight outpouching throughout 

 the extent of which the muscle processes are wanting. The ectoderm 

 of the Verrucae consists of slender cells, closejy set and uniform in 

 character, there being no trace of gland cells, such as occur in the 

 rest of the column ectoderm and no pyriform cells. In the in- 

 dividuals in which the Verrucae are confined to the upper part of the 

 column the mesogioea of the lower part is raised into strong ridges 

 which give the reticulated appearance already described. The 

 pseudo-acrorhagi present the some structui-e as the rest of the 

 verrucal portion of the column, except that the mesogioea is some- 

 what thinner. There is practically no sphincter muscle, the few 

 muscle processes occurring where it should be found being scattered 

 and no larger than those of the general column wall. 



The longitudinal muscles of the tentacles and the radial muscles 

 of the disc are feeble and are throughout ectodermal. The mesogioea 

 of the tentacles is very thin. 



The stomatodaeum is strongly ridged longitudinally and is pro- 

 vided ^ith two distinct siphonoglyphs. The mesenteries are ar- 

 ranged hexamerously in four cycles, the first three of which are per- 

 fect, though losing their connection with the stomatodaeum at 

 different levels, those of the first cycle, which includes two pairs of 

 directives, being attached lower down than the others. The mesen- 

 teries of the fourth cycle difi'er a little in the extent of their de- 



