ACTINIARIA 



As we see, the size of the nematocysts and the spirocysts agrees well in the different specimens. The 

 nematocysts of the column are shorter than those of the tentacles, in five more closely examined specimens 

 1214 x 1,5 p, 1214 x i p; 1823 X 1,52 ft; 1719 X 1,5 ft, 2023 X 2 ft. 



Me. Murrich has found embryos in the coelenteric cavity in May, I myself in June, July, August 

 and October. 



Cribrina spetsbergensis (n. sp.). 



PI. 2. Fig. 2. 



Rhodactinia crassicornis (O. F. M.) var. spetsbergensis Carlgren 1902 p. 39, textfig. 3. 

 ?Leiotealia spetsbergensis n. sp. Kwietniewski 1898 p. 134 (pro parte). 



Diagnosis: Column with commonly rather small verrucae, at least in the upper part. Sphincter 

 palmate or pinnate. Tentacles in variable number unto 96, thick, cylindrical, in contraction smooth or more 

 seldom longitudinally sulcated, at most as numerous as the mesenteries, all of about equal length. Longitud- 

 inal muscles of the tentacles well-developed with in general high folds, principally ectodermal, but at the 

 base of the folds and sometimes at their apex in small parts enclosed in the mesogloea. Radial muscles of the 

 oral disc like the longitudinal muscles of the tentacles but more enclosed in the mesogloea. Mesenteries of 

 variable number unto 49 pairs, commonly hexamerously but often irregularly arranged, so that not all me- 

 senteries of the last cycle are developed. Muscles of the mesenteries strong, especially the longitudinal and the 

 parietobasilar muscles. Reproductive organs on all the stronger mesenteries, sometimes also on the directives. 

 Nematocysts of the tentacles (24) 26 42 X 23 ft, those of the actinopharynx (34) 36 53 X 3,5 5 ft, spiro- 

 cysts of the tentacles (18) 22 X i 1,5 to 53 x 2,5 ft. 



Colour? 



