225 
dumene with each other they also seem not to be related to each 
other. The thing is I cannot accept Stephenson’s interpretation that 
the mesenteries in Diadiimene (Metridium) schilleriana are divisible 
into macrocnemes and microcnemes. It is not certain that An nan¬ 
dal e has always sectioned the whole specimens, and in that case 
it is possible that gonads, filaments and pennons were always pre¬ 
sent also in the stronger imperfect mesenteries. (Compare Diadii¬ 
mene neozelanica, where these organs begin rather far down on 
the imperfect mesenteries). In each case there is in some indi- 
viduals in Diadumene, in opposition to Åcraspedanthus, no distinet 
difference between the mesenteries of the first and the second 
order. To my mind Diadumene is more allied with the genus Åi- 
ptasia than with Åcraspedanthus (compare Diadumene p. 234). Con- 
cerning the last genus I think we can, at least provisionally, place it 
among the Phelliidae. It agrees with Phellia in almost all char- 
acters Only the structure of the column is different, in Phellia 
the column is divisible into scapus and capitulum, in Araspedanthus 
not. Further the cinelides are absent in Phellia, present in Acra- 
spedanthus. I am, however, of opinion that we can hardly base 
family characters on the presence or absence of cinelides. Steph¬ 
en son as well as I myself have shown that cinelides may appear 
or be låcking in species belonging to one and the same genus 
outside the old Sagartiidae. Besides, we are at present far from a 
satisfactory classification of the Actinians with acontia. Only when 
the anatomy of these forms shall have been revised and their nema- 
tocysts in the acontia examined, the relationship between the genera 
can be expected to be brought to a close. 
Åcraspedanthus elongatus n. sp. 
Diagnosis. Body cylindrical, pillarlike, also in very contracted 
State mostly higher than broad. Sphineter close to the tentacle base, 
reticular, wholly separated from the endodermal circular muscles. 
Tentacles 6 + 6 + 12-1-24 +an incomplete fifth cycle. More than 
half the oral disc provided with tentacles. Actinopharynx more than 
one third of the length of the body with about 14 longitudinal 
ridges. Pairs of mesenteries 6 + 6+12 +an imperfect fourth cycle 
only in the uppermost part of the body. 2 pairs of directives, 
Pennons very strong, circumscript. Nematocysts of the column 
Vidensk. Medd. fra Dansk naturh. Foren. Bd. 77. 
15 
