62 
Fig. 56. Euantipathes dichotoma (Pall.) n. n. a, b Polyps; 
a, b 14 X- 
diminishes regularly. The spines (fig. 54) are arranged in 6 longitudinal rows, alternating in 
a quincunx. Their surface is smooth and on the younger parts (fig. 54 d) their shape is more 
slender than on the older parts of 
the colony (fig. 54^). Their mutual 
distance is 375 y. and their length is 
the same on all sides of the axis : 
150 y.. They are visible through the 
coenenchyma and the periphery of the polyps. The polyps (fig. 55, 56, 57) are visible to the 
naked eye as white cushions, placed in a single series, 
but not on a special side of the axis; often the line 
of polyps is wound round the axis, and on the older 
parts some polyps deviate from the single row. Polyps 
and coenenchyma are very transparent. The sagittal 
tentacles are inserted at a slightly lower level and 
the proximal lateral ones are larger than the distal 
ones; the base of the tentacles is swollen, the top is 
more slender. Length of the sagittal tentacles 0.55 mm., 
of the proximal lateral ones 0.85 mm., of the distal 
lateral ones 0.55 mm. The intertentacular distance is 1.4 mm., and there is a cross-groove 
between the polyps and a clearly visible straight longitudinal groove on 
the back of the axis. Young polyps alternate rather regularly with the 
adult ones. Colour : white or greyish. The oral cone is low, with a small 
round mouth. Usually the oral cone is invisible while the tentacles are 
covering it. — Coenenchyma and polyps show little milkwhite spots. The 
darkbrown mesenterial filaments are very conspicuous in all polyps. 
The complete colony of station 310 is 10.5 cm. in height; the 
diameter of 825 y. at the base remains subequal; at the top a swift tapering 
takes place. The same holds true for the branches. The slightly sinuous stem bears two rows 
of branches, both in the same plane, alternating 
regularly to the right and to the left, with a varying 
mutual distance of 1 — 2 cm. in a row. The angle 
of insertion is 30 0 - and the branches are on their 
further course curved distally, till they are sub¬ 
parallel with the stem. The secondary branches 
are inserted at the same angle and have the same 
course, but they are inserted only on the convex 
side of the primary branches. The same holds true 
for the branches of the 3 rd and the 4 th order; all 
branches lie almost in the same plane. The spines 
(fig. 58^) are blunt, triangular, with their distal 
side at right angles with the axis, smooth or slightly rough with irregular grooves. The length 
Fig. 57. Euantipathes dicho- 
toma (Pall.) n. n. Tentacle 
filled with mesenterial fila¬ 
ments; 52 X- 
Fig 58. Euantipathes dichotoma (Pall.) n. n. a Spines on 
the base of the colony; b spines on a branch; a, b 52 X- 
