The Actiniae of tlie Plate CoUection. 229 



present in miicli less quantity, indeed, in tlie smallest individual 

 examined it could not be perceived. The adults also sliow a difiuse 

 j^ellowisli pig'ment in tlie cells of tlie ectoderm. 



Tlie longitudinal musciilature of tlie tentacles and tlie radial 

 muscles of the disc are moderately developed and are confined to 

 tlie ectoderm. The stomatodaeum is long, reaching nearly to the base 

 and it is deeply grooved longitudinally (Fig-. 8). In all the speci- 

 mens examined it possessed two well deflned siphonoglyphs, whose 

 endoderm was mnch higher than that of the general snrface of the 

 stomatodaenm, presenting an appearance siniilar to what I have al- 

 ready described (1901) in Crihrina eleganUssima. 



The mesenteries in the adiüt specimens are arranged hexamer- 

 oiisly in four cycles, a few pairs only of the fifth cycle being de- 

 veloped. There are two pairs of directives and the mesenteries of 

 the first three cycles are perfect, only those of the first cycle, 

 however, being attached throughont the entire length of the stomato- 

 daenm. The longitudinal muscles on the members of the first cycle 

 are only moderately developed, and, in the upper portions of the 

 mesenteries, form a low diffuse pennon tapering gradually at either 

 edge; lower down, however, below the level of the stomatodaeum, 

 they become narrower and higher, tapering gradually toward the 

 outer edge but terminating abruptly internally. A well developed 

 parieto-basilar occurs, extending almost up to the disc; its mesogloeal 

 folds for the support of the muscle fibres are decidedly feeble, but 

 the inner edge of the muscle forms a distinct fold on the snrface 

 of the mesentery. The mesenteries of the fourth (and fifth) cycle 

 are destitute of a muscle pennon and develope no mesenterial fila- 

 ments. No reproductive organs were present. 



In the young individuals the mesenteries are fewer, there being 

 but three complete cycles and in the smallest specimen examined 

 the mesenteries of the third cycle were rudiments. Occasionally 

 pairs of the fourth cycle were seen. Only the first cycle mesenteries 

 were perfect, those of the second cycle just touching the stomatodaeum 

 at its oral end. In one of the young individuals a fusion of the 

 free edges of a pair of mesenteries was observed, the phenomenon 

 occurring in two pairs of mesenteries belonging to the second cycle 

 (Fig. 8). In both pairs the mesenteries were separate in their upper 

 parts, the fusion beginning about half way down and, in one pair, 

 extending only for a short distance, while in the other it continued 

 to the base. 



