34 
of the ultimate branches, etc. For the present I think it will be desirable to join Brook’s 
Arachnopathes actileata to Arachnopathes ericoides , since the differences, mentioned by Brook, 
appear to me as only of a qualitative value, e. g. the somewhat less frequent fusions of the 
branches, the tendency of the branches to be inserted on one special side of the branch of 
lower order (also to be remarked in both Siboga-specimens), the double spiral distribution of 
the spines (also present in both Siboga-specimens), the somewhat smaller spines, which are 
sharper, etc. In many of these points the Siboga-specimens occupy an intermediate position 
between both of Brook’s species. — Arachnopathes clathrata M. Edw. is too imperfectly described 
to permit a decision to be taken on the relationship of this species and Euantipathes ericoides , 
but the difference is certainly not very great (cf. Brook’s figures of the spines). At various 
points this species is like Eziantipathes dichotoma , but the very frequent fusions, even between 
the ultimate branches, make a different type of it, although it is to be remarked that this is 
no very great difference and that various specimens of Eu,antipathes dichotoma may be regarded 
as transitions, e. g. XXVII, XXV, XIX, XXXI and XXXV, which in the here-given order 
show an increasing number of fusions, but always in the older parts of the colony and never 
to such a high degree as in this species. — It is not necessary to keep the genus Arachno¬ 
pathes M. Edw. intact, since the mode of branching is not so very typical, as is demonstrated 
by the colonies of Eicantipathes dichotoma , which also show fusions, while the fact that the 
branches are fused into a mass, several centimetres in thickness instead of being flat, can 
surely be of no generic value, since colonies of very different genera show also a non-flat shape, 
near other species of the same genera which are flat. -— The polyps, described here for the 
first time, leave no doubt as to their being in accordance with the Euantipathes- polyp-type. 
Diagn osis : 
Colony : densely branched and through numerous fusions fused into 
a dense mass. No principal stem, but several equivalent branches, sub- 
vertically growing and presenting dilations without regularity. All bran¬ 
ches curved upwards-, angle of insertion 6o° to 90°. Ultimate branchlets 
arranged spirally or irregularly. The branches have a tendency to an 
unilateral arrangement. 
Spines : slightly distall y inclined; concave distal side, convex proxi¬ 
mal side; smooth; 4— 5 longitudinal rows and quincunx. Length 90—120 p„ 
distance 240— 270 p.. 
P olyps : arranged in a single series, but not on a special side of the 
colony: rare or absent on the older parts. Inter poly par distance 1.1 — 
1.25 mm. Sagittal tentacles 0.35 mm. long; proximal lateral ones (0.3 mm.) 
slightly predominating. Dome-shaped oral cone with round or somewhat 
sagittally elongated mouth. 
9. Euantipathes ? ctirvata sp. n. (PI. VIII, fig. 5). 
Merauke, Dutch South New Guinea. 1 spec. 
This dried colony, collected by Dr. J. W. R. Koch, is fixed with an irregular basal plate. 
