the Actiniarian Family Aliciide. 13 
the exception of an occasional isolated cell, is homogeneous 
in structure. It is plaited a little on both the ectodermal 
and endodermal borders for the support of the musculature. 
The endoderm-cells are often very long in section, the layer 
having irregular internal boundaries. Zooxanthelle are 
present. 
Disk.—The ectoderm is thick and ciliated; elongated 
nematocysts are present; the mesogloea and endoderm are 
the same as in the tentacles. An endodermal musculature is 
seen. 
Gsophagus.—The cesophageal walls are much folded, but 
there is no indication of any special groove; the ectoderm and 
endoderm are much thicker than the mesogloea. 
The ectoderm is richly ciliated, and, in addition to the 
outer zone of narrow nematocysts, contains abundant irregu- 
larly distributed large stinging-cysts. The nuclei are arranged 
in a broad zone; a very weak ectodermal muscle is seen in 
transverse sections, and a similar endodermal muscle in longi- 
tudinal sections. 
Mesenteries.—In the region of the cesophagus twelve pairs 
of perfect mesenteries, including two pairs of directives, are 
present, and pairsof very short imperfect mesenteries alternate. 
They are broad towards the column-wall, but narrow towards 
the cesophagus ; zooxanthelle are sparingly present in the 
endoderm. ‘The longitudinal retractor muscles are well 
developed for some distance on one side and the mesogloea is 
thrown into supporting folds. Below the cesophagus the 
mesenteries branch, the endoderm becoming much thickened ; 
each division is terminated by a rounded mesenterial filament 
bearing abundant nematocysts, and continuous with the 
ectoderm of the cesophagus. 
Gonads.—No reproductive cells were present in any of the 
examples sectionized. 
The distinctions between these two species are, in several 
respects, those of degree rather than of kind. Practically all 
the characters strongly marked in the first appear to be 
present in the second, but developed to a less extent. The 
average dimensions of the Antillean representative are two or 
three times those of the Mediterranean specimens received. 
Of a score of specimens received from Naples, preserved in 
4 per cent. formalin, none exceeded 0:4 centim. in diameter 
across the base, while an average diameter of the Jamaican 
forms is 1°3 centim. The colour distinctions may be of some 
moment. ‘The column in Andres’s species has yellowish- 
brown-ochre bands; these are never met with in the new 
