I have made use of the terminology of van Beneden, while I follow Brook in the 
choosing of the sagittal and transversal axis of the polyps, notwithstanding Schultze’s remarks 
on this subject, which are in my opinion refuted by the results I obtained. 
MICROSCOPICAL-ANATOMICAL DESCRIPTION. 
i. Eucirripathes anguina (Dana) em. 
* 
Tentacles (PI. I, figs, i, 2 and 3). The ectoderm is 80 p and papillose, with a 
thickness of 25 p between the papillae. In these papillae the epithelial cells diverge fan-like 
towards the periphery. There are no nematocysts. Deeply staining granular glandcells are rather 
numerous in some places, especially near the base of the tentacles, but in other places they 
are absent. The fibrillar nervous layer is separated from the mesogloea by a clear space. There 
are longitudinal musclefibres, lying against short mesogloeal lamellae, which are continued by 
the bases of the epithelial cells. The mesogloea, 80 p at the tentacular base and 20 p at 
its top is a homogeneous layer, in which there are a few cells distributed in an irregular 
manner. These sharply defined cells are oval or round but never stellate. Their diameter is 
5 p and they have a large round nucleus. The entoderm (50 p) contains hyaline glandcells 
but no deeply staining glandcells. The entodermal cells are slightly deeper staining than the 
ectodermal cells. There is no nervous layer. There are circular musclefibres, sustained by the 
same mesogloeal lamellae as in the ectoderm: these fibres are less developed than in the ectoderm. 
The bodywall (PI. I, fig. 4) is of the same structure as the tentacles, except that the 
crowdings of deeply staining glandcells are very extensive in the ectoderm. These glandcells 
extend over the entire height of the ectoderm or over its basal half only. There is no entodermal 
muscle-layer but the ectodermal fibres are visible although less than in the tentacles; their 
direction is parallel with the axis of the colony and they are supported by small mesogloeal lamellae. 
Actinopharynx (PI. V, fig. 15). Its narrow lumen is very much sagittally elongated and 
the wall is folded in concord with the places of attachment of the mesenteries, especially in 
the upper part of the actinopharynx. The ectoderm (25 — 50 p) contains many large hyaline 
glandcells together with a superficial layer of deeply staining actinopharyngeal glandcells, which 
makes this ectoderm easily to be distinguished from the ectoderm of other parts, except for the 
mesenterial filaments. The sagittal ends of the actinopharynx have a thicker ectoderm but of the 
same structure as the rest; they descend to a greater depth than the rest of the actinopharynx. 
In several places, especially near the middle of the actinopharyngeal lumen, the ectoderm contains 
an accumulation of vellowbrown pigment, the granula of which are 1 p or less in diameter. There 
are no nematocysts or musclefibres. The mesogloea is only 2.5 p thick, and increases in 
thickness on the places of attachment of the mesenteries. The entoderm (12 — 18 p) contains 
only a few glandular elements, and no musclefibres. 
Mesenteries (PI. I, figs. 5, 6, 7, 8, 10 and 11; PI. V, figs. 10, 11, 12, 13, 14, 15, 16 
and 23). The course of the mesenteries sometimes is not easily to be distinguished through the 
