ACTINIARIA 



This genus and Urticina are very easily confounded. They are distinguished from one another by 

 the distribution of the reproductive organs on the mesenteries, and by the different relation of the nemato- 

 cysts in the tentacles to those of the actinopharynx. If it were to be found out in future that Urticina in 

 its first adultness has reproductive organs also in the mesenteries of the first cycle, which I hold improbable 

 (compare Urticina felina p. 167, 168, 174), and that these reproductive organs are later on reduced, the only 

 important difference between the two genera lies in the above named different size of the riematocysts. 

 Under such circumstances it is possible that we must drop the above genus and place it together with Ur- 

 ticina. So far, we have every reason for preserving it. 



Cribrinopsis similis n. sp. 



(PI. 3. Fig- 7)- 



Rhodactinia crassicornis (O. F. Mull.) pro parte Carlgren 1902 p. 39 textfig. 6. 

 PUrticina crassicornis (O. F. Mull.) and Rhodactinia Davisii Agas. pro parte. Auctorum. 

 Actinostola abyssorum Carlgr. Pax 1915. 



Diagnosis: Pedal disc wide. Column at least in the upper part with verrucae (sometimes incon- 

 spicuous or not present?) Sphincter pinnate to palmate. Tentacles in larger specimens from 64 to 90, com- 

 monly almost as numerous as the mesenteries, the inner longer than the outer; thick, cylindrical or a little 

 conical, more robust than those of Urticina, in contracted state irregularly wrinkled or longitudinally sul- 

 cated with numerous transversal folds. Longitudinal muscles of the tentacles very strong, mesogloeal meshes 

 fine, radially extended. Radial muscles of the oral disc strong between the radial furrows, in the furrows 

 feeble, mesogloeal muscles fusing into the ectodermal muscles. Mesenteries commonly decamerously, 

 more seldom hexamerously, sometimes a little irregularly arranged. Nematocysts in the ectoderm of 

 the tentacles 34 70 X 2 2,5(3) p, in that of the actinopharynx 36 67(70) X 3,5 5 ;i. Spirocysts of the 

 tentacles of variable size from 19 X 1,5 to 67 X 3 p. 



Colour? 



Dimensions: The size of some of the largest, strongly contracted specimens was the following: 



1) Spec, from Ikamiut: largest breadth 9 cm, height about 3 cm, length of the inner tentacles about 1,7 cm. 



2) Spec, from Behring's Sea: largest breadth 8,5 cm, height 7 cm, length of the inner tentacles 3,5 cm, that 

 of the outer 2 2,5 cm. (The tentacles were not strongly contracted). 



Occurrence: New Foundland ? (The bottle, containing also several Urticina was labelled Green- 

 land and New Foundland). 



West Greenland. Ritenbenk 15 20 fms. (Oberg 1870) (Traustedt 1892). Godhavn 

 70 fms. (Torell). Claushavn 10 15 fms. ; 20 fms. (Oberg 1870). 

 Christianshaab 1530 fms. (Oberg 1870), Ikamiut (I/ohmann 

 1905). Egedesminde (Traustedt; BergendaliSgo). NordreStram- 

 fiord 1438 m. (Nordmann St. 3 b). Sukkertoppen 15 26 

 fms. (Oberg 1870, Holm and others), Fiskenaes 63 N. 5iio' 

 W. 150 fms. (Ammondsen). Bredefiord 170180 fms. (Rink- 



