242 J- Playfair McMürrich, 



descriptioii and figiire of A. Mcolor, one cannot fall to be Struck by 

 its great similarity to A. nivea, the principal difference being- appar- 

 ently the color of the tentacles which in hicolor were emerald green. 

 From what we know of the-, variability in color in Actinians one 

 may be inclined to doubt the sufflciency of a diiference of this kind 

 for the Separation of the two forms, but until we possess an an- 

 atomical description of hicolor it seems well to leave them distinct, 

 since a fusion would necessitate the abolition of the term nivea. 



7. JParactis if/nota n. sp. 



No. 61a. Iquique. 2 specimens. 



The base is adherent and somewhat sraaller than the column 

 (Fig. 20), and in both specimens is somewhat irregulär in outline. 

 The column is about 1.2 cm in height; it is somewhat irregulär in 

 cross section, its walls are thin and much wrinkled by contraction 

 especially in the proximal portions, and there is no indication of 

 acrorhagi, tubercles, or capitular ridges, the margin being but faintly 

 marked. The tentacles number about ninety-six and are moderate 

 in length, conical and somewhat slender; they are exposed in both 

 specimens. There in no trace of color remaining in either tentacles 

 or column. 



Structure. The column mesog'loea is thin, though somewhat 

 thicker than the ectoderm and has a markedly fibrous structure. 

 The circular muscles are rather feeble and in the upper part of the 

 column there is a thin though broad mesogloeal sphincter (Fig. 21). 

 It is elongate triangulär in form, reticular in structure and is 

 separated from the endoderm by a narrow layer of mesogloea, while 

 although very close to the ectoderm above, it separates from it 

 below so that its lower part lies almost in the middle of the mesogloea. 



The tentacles are thin-walled and their longitudinal muscles are 

 not imbedded in the mesogloea. The stomatodaeum possesses two 

 rather shallow and small siphonoglyphs. 



The mesenteries are arranged hexamerously in three cycles, 

 with occasional representatives of a fourth. Those belonging to the 

 first two cycles are apparently perfect and they alone possess well 

 developed muscle pennons (Fig. 22), which occupy about one-half 

 the surface of the muscular portion of the mesenteries, tapering 

 abruptly at their inner edges, but very gradually externally. A weak 

 parieto-basilar can be distinguished but it does not extend as high 

 as the stomatodaeum. The mesenteries of the lirst and second 



