40 ARVID R. MOLANDER, ALCYONACEA. 
found. For this reason, I consider, I cannot retain Erythropodium norvegicum (sensu 
BRocH) as a distinct species, especially as the original and most important characteristic 
of this species, the membranous mode of growth, is altogether worthless. On the other 
hand, the Alcyonmium digitatum includes two different types and may be divided into 
two varieties ÅA. digitatum var. digitatum and ÅA. digitatum var. norvegicum; the latter 
is identical with Hrythropodium norvegicum (sensu BROocH). 
Alcyonium digitatum var. digitatum n. var. 
Diagnosis: The spicules of type I. 
HICKSON, in his excellent monograph on Alcyonmium digitatum, points out diver- 
gencies between the spicules of the different varieties. It seems, however, from his 
illustrations of spicules, that the white variety mentioned by him corresponds with the 
var. digitatum. The measurement of the bark spicules: 0,10—0,15 mm., of the spicules 
of anthocodia: 0,35 mm. 
Within the var. digitatum is found, beside the membranous colonies, stunted, unde- 
veloped colonies, which are of interest on account of their interior construction. (Pl. IT, 
fig. 24—26.) 
In most cases the coelenterons of the polyps reach right to the base of the colony. 
The endodermal, indirect canal system is, as yet, poorly developed, and there is found 
instead a direct connection between the coelenterons. In the older specimens, however, 
the direct connection has generally disappeared, and only the indirect vessel-system 
appears. The crowding among the numerous coelenterons of the polyps in the, as yet 
but slightly developed, colony may be considered as an explanation of the direct connec- 
tion. In other respects, this offers a parallel to the conditions in a number of species 
referred to Gersemia (sensu MOLANDER), where the canal system is direct. 
Habitat: 
Sweden, off Helsingborg, 32—40 met. sandy loams, THÉEL, TRYBOM 1878. Mar- 
strand, N. Astol—-Moholmarna, 36—80 met. LAGERBERG 2/, 1906, 1 sp. Gullmaren, 
Spättan—Bondhålet 27 met. Kristineberg zool. station 1909 1 sp. Gullmaren, Löken, 
Kristineberg zool. station 1909 7 sps. Koster Fiord, 9—27 met. rocky bottom, LJUNG- 
MAN 5/, 1865 1 sp. 
Further distribution. 
Sweden, Skåne, Öresund, 23—24 met. (LÖNNBERG 1898). Bohuslän, Gullmaren 
(THÉEL 1907). Denmark, off the west and east coasts of Jutland, Cattegatt, Öresund, 
10—40 met. (LEVINSEN 1893).: Denmark, Lim Fiord (MORTENSEN 1897). Norway 
On this locality also ÅA. digitatum var. norvegicwm may occur, but the author does not distinguish 
between the two varieties. 
