ACTINIARIA 



Colour: Specimens living on Primnoa yellow with salniond-red filaments, those on Muricea bine 

 (Nordgaard). 



Dimensions: Proximal part of the animal to about 7,5 cm broad. Length of the tentacles 1 — 1,5 cm 

 (Appellof). Specimen from the Ingolf-Exp. (compare below). 



Occurrence: Norway. Drontheimfiord 100 fms. on Muricea placomus and on Prinuioa lepadifera 

 (Nordgaard, G. O. Sars) 



N. of Iceland, 66°3' N. 20°o5' W.44 fms. Temperature at the bottom 5,6° (Ingolf-Exp. St. 127) i sp. 



The anatomical description of the species given by Appellof. I have further completed in 1914 

 and, among other things, I have pointed out the presence of the curious, half-funnel-like formations 

 on the imperfect mesenteries. I now want to add something to this, especially with regard to tlie actino- 

 pharynx. The specimen dredged by the Ingolf-Expedition is much smaller than the specimens described 

 by Appellof, has produced only few reproductive elements and is very contracted. The diatneter of the 

 pedal disc was 2 cm, the height of the column i cm and the breadth at the distal end about i cm, the great- 

 est length of the tentacles 1,2 cm. The tentacles were only 40 in number. The outer habitus of this specimen 

 agrees ver>' well with the description which Appellof gives of the species, and very much resembles the 

 specimen reproduced in fig. i in the paper by Appellof, though the body is a httle higher (PI. 3. fig. 6) 

 and the mouth is almost closed and sourrounded by a wall rising above the other part of the oral disc. From 

 the upper rim of this wall (opening of the mouth?) to the lower end of the actinopharynx the distance is 

 0,35 — 0,45 cm (in reality the distance is a little greater, as the undermost part of the actinopharynx is bent 

 outward). The whole thing looks as if the actinopharj-nx is much longer than stated by Appellof. As how- 

 ever no distinct limit exists between the oral disc and the actinopharynx — the ectodermal radial muscles 

 and the radial furrows on the oral disc are prolongated as longitudinal nmscles resp. longitudinal furrows 

 into the actinopharynx (a factum already emphasized by Appellof) and tlie occurrence and the size of 

 the .stinging capsules are the same in l)oth regions — it is almost impossible to decide, where the actino- 

 pharynx begins. If we are of the same opinion as Appellof and regards the actinopharymx as reduced to a 

 thin joint, the animal has tlie capability — as the Ingolf-specimen shows — of turning down the central 

 parts of the oral disc, so that they look like the actinopharynx, and "the mouth" is not on the rim of the 

 actinopharynx, but completely surrounded by the oral disc. If in opposition to tliis we consider that the 

 actinopharynx begins at the "mouth", the actinopharynx is nowise as much reduced as Appellof assures, 

 though on such a supposition certainly short. I therefore hold it best to modify a little the diagnosis of the 

 genus concerning the length of the actinopharynx. Furthermore the actinopharynx of the Ingolf-specimen 

 shows the same appearance as that of the specimen described by Appellof, the prolongations of the ac- 

 tinopharynx on the mesenteries are however not as strongly folded in the former. Concerning the inner 

 organisation I cannot give any information of the arrangement of tlie mesenteries as I have not found it 

 desirable to totally sectionise the specimen. The half-funnel-shaped formations on the imperfect mesen- 

 teries agree in their structure with those described by me before (19 14). The glandular streaks were very 

 meandrian, and the slightly developed reproductive organs were hmited to the lower parts of the mesen- 



