KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 51. N:o |l. 19 
strings or rows of cells. In the case of the Alcyonium, where in general the collection of 
the polyps is larger, we find an arrangement of the canal system which is mentioned 
on p. 9. At the base of the coelenterons there will be found, in addition to the indirect 
connection, a few direct canals. The vertical canals are here but slightly developed. 
The Gersemia-species often lack similar, large collections of polyps, but where such oc- 
cur there will be found conditions almost similar to those in Alcyomum, although gener- 
ally with a greater development of the vertical canals. A large gathering of polyps is 
hardly ever produced in the case of Gersemia, without a trunk being also developed, in 
which the canal system mostly consists of direct canals. The membranous formation 
in the case of Alcyonium often changes, so that the whole, membranous, polyp-bearing 
part takes on the form of a conical or head-like swelling. Gersemia-species generally form 
small trunks with, at first, an insignificeant number of polyps. These membranous forms 
are much like the family of Cornulariidae, and a good many of them have even been class- 
ed with fam. Cornulariidae. "The Alcyonium species have been classed with Sympodium, 
as is, for instance, the case with ÅA. digitatum var. norvegicum; but, according to KÖKEN- 
THAL (1906), the great majority of the species of Sympodium are nothing but membran- 
ous forms. In the case of Sympodium abyssorum, DAN., we find a membranous form of 
Gersemia fruticosa, and the same is case with Sympodium hyalinum, GRIEG. But Clavularia, 
too, has been increased by membranous forms of other genera. BROocH classifies with 
this (1912) Sympodium hyalinum (= Gersemia fruticosa forma membranea), GRIEG (1887), 
DANIELSEN (1887) a small membranous form of G. fruticosa, which he names Clavularia 
frigida, KÖKENTHAL (1906) transfers to this GRIEG's Sympodium margaritaceum, and 
WRIGHT and STUDER the antarctic Clavularia cylindrica, which is a membranous Ger- 
semia species. It has been the purely external formation which has here been taken 
into consideration. An investigation, however, of the spicules and the canal system 
ete. in respective forms shows at once that the accepted relationship is incorrect. In 
the case of the forms mentioned they show constant Alcyonium- or Gersemia charac- 
teristics. 
As has been proved most of the species described as Sympodium can not belong 
to this genus. KÖKENTHAL (1906) has strictly limited the genus Sympodium, and he 
refers to Sympodium only S. coeruleum, EHRENBERG. KUKENTHAL considers Sympodium 
to belong to Cornularvidae and indicates the peculiar spicules and the growth of colonies 
and the power of total retraction of this species also as characteristics for the genus. The 
membranous or stoloniferous growth of the colonies also occurs within other genera 
which do not belong to Cornulariidae. ”Phe spicules prove a higher differentiation than 
that which generally occurs in Cornulariidae (p. 25). The power of total retraction of 
polyps can not occur within Cornulariidae (p. 22). According to KÖKENTHAL, only 
pure basal canal system without vertical canal or strings occurs within Sympodium. 
This is possibly correct, but it is by no means proved that this is the case in the species 
which may be considered as Sympodium. With the Sympodium catenatum (FORBES) 
we also find vertical cell-strings. Other characteristics do not indicate anything of the 
nature of Cornulariidae. Nor can I consider Sympodium belong to Cornulariidae. 
(Compare p. 32.) 
