3 6 
of spines of the same type; length 30 y on the upper-frontal side of the axis and 15 y on 
the other side; distance 225 — 300 y. 
The badly preserved polyps are placed on the front of the branched part of the stem 
and the upper-frontal side of the branches. The tentacles are transparent, thin and long: 1.5 — 
2 mm. Sometimes they attain a length of 2.5 mm. but on the older parts also shorter tentacles 
occur. The distance between the pairs of tentacles is fully 2 mm. 
In the table (pg. 35) I have shortly mentioned the characteristics of the “Siboga'’-specimens 
and of the other known species, wherefrom Bathypathes lyra Brook is excepted, just as Bathypathes 
bifida Thomson, since the mode of branching of both species, especially with the latter one, is 
of a sufficiently clear specific character. I have included Bathypathes tenuis Brook in the list, 
to demonstrate how the characteristics of this species also melt imperceptibly into those of the 
other species, so that only the few remnants of secundary branches of Bathypathes temris are 
the reason why this species has been left intact; for I have no reason whatever to suppose 
that secundary branches occasionally occur in the species the branches of which are simple. The 
data of the species described by Brook are derived from his descriptions and from the figures, 
in so far as it was possible. Grouping the specimens and species according to the different 
characteristics, we get the following groups : 
In type of colony belong together: I, II, Ilia and p, IV, Va and p, B. erotema in 
one group, and B. pahtla, B. patula var. plenisp ., B. tenuis and B. alternata in a second group. 
In diameter of the stem belong together: I, Va, B. erotema (and perhaps B. 
alternata and tenuis ) in one group; II, IV, Vp in a second group, and Ilia and p, B.patula 
and its var. pi. in a third group. 
In angle between branch and stem belong together: I, III p, Va and p in 
one group; II, Ilia, B. patula and its var. plenisp. in a second group while the other three 
are each different from one another and from both groups, however without a very sharp distinctive. 
In angle between the pairs of branches there are three groups: I, II and 
I\ in the first one; III a and p, V a and p, B. erotema and B. patula var. plenisp. in the 
second one, and B. pahtla , alternata and tenuis in the third one. 
In distance of the pairs of tentacles II and B. patula form one group, and 
IIIp, V p, B. erotema and B. alternata a second group. 
In length of tentacles II and B. pahtla form one group, IIIp, B. alternata and 
B. erotema a second group while Vp holds the middle between both groups. 
In length of the spines belong together: I, II, Ilia, IV, B. tenuis and B. erotema 
in one group; IIIp, \ a and p in a second group and B. pahtla , its var. plenisp. and B. 
alternata in a third group, which has. transitions to the first group. 
In number of longitudinal rows I, II, IIIp, IV, Va and p, B. erotema , B. 
patula var. pi. and B. alternata form a group, and the other three are each slightly different 
from this group and each other. 
In the further regularity in spines-distribution I, II, B. pahtla and its 
var. pi. form a group, which by Ilia and B. alternata is connected with the third group of 
IIIp, IV, V a and p, B. temtis and B. erotema. 
