ACTINIARIA 



capitulum about 14 p long. Tentacles 16. Nematocysts of the tentacles 19 26 x 2 2,5 /*, their spirocysts 

 12 24 X about 3 IJL. Nematocysts of the actinopharynx partly 29 41 X 3 3.5 p, partly (24) 26 34 X 

 4 6 p, the latter with discernible basal part to the spiral thread. Longitudinal muscle-pennons with few, 

 10 13 folds, only branched in the outer part. The outer lamellar part of the mesenteries attached to the 

 pennon next to the outside. Parietal muscles ordinarily developed, in transverse sections through the 

 distal part of the column looking like a half-opened fan. The expansion of the parietal muscles on the 

 column considerable. 



Colour in alcohol, rusty- to ochreous-coloured, in the distal part sometimes dirty -grey. 

 Dimensions in contracted state. Length to about 0.9 cm, breadth to about 0.35 cm. 

 Occurrence. East-Greenland. Mackenzie bay north of Franz Joseph's fiord 12 -35 m mud (Sw.- 



Polar-Exp. 1900. N. 17) 2sp., Scoresby Sound Famae islands 7O5'N. 

 2233' W. 5 9 m mud (Sw.-Greenland-Exp. 1899 No. 32) 5 sp. South 

 of the little Pendulum island 7435' N. i823' W. 18 21 m mud and 

 sand (Sw. Greenland Exp. 1899 No. 20) i sp. 



Jan Mayen 7ii2' N.828' W. 1275 m grey clay (Sw. Greenland-Exp. 1899 No. 17) i 



sp. (badly preserved and young specimen, determination dubious. 



Nova Zembla Matotschkin Sharr 2 5 fms. day and sand (Nova Zembla-Exp. 1875 



No. 80). 

 Kara Sea 7338' N. 6345' E. 80 fms. shells (Nordenskiold-Exp. 1876, No. 38) 2 sp. 



Exteridr aspect. The physa is ordinarily developed and perforated by apertures. The scapus 

 is provided with a periderm, most developed in the proximal part, the distal part of the scapus is polygonal. 

 The nemathybomes are rather large, possibly a little irregularly arranged in the proximal part ; in the distal 

 part they form an undulating row in the middle of each compartment. It is probable that the nemathybomes 

 are grouped in 8 longitudinal rows, but as all the animals were very strongly contracted this arrangement 

 may have been disturbed by the contraction. The capitulum is of usual appearance. The tentacles are 16 

 in number. The actinopharynx and the siphonoglyphe were not well preserved. 



Anatomical description. The ectoderm of the physa is high with scattered nematocysts, 10 14 p 

 long. To the physa foreign bodies sometimes adhere. The ectoderm of the scapus is rather high with an or- 

 dinarily developed periderm, to which a great many foreign bodies are sticking. The nematocysts of the 

 nemathybomes are numerous. A general view of the size of the nematocysts of the examined specimens 

 shows as follows. 



in the (b) nematocysts of the actinopharynx the basal part to the spiral thread is discernible. 



