50 



ACTINIARIA 



The statement of Danielssen, that the capituluni has suckers, is not correct. The tentacles were i6 in the 

 specimen from Great fiord, Wijde bay and in the examined type-specimen; the specimens from Greenland 

 had only 13, resp. 15 tentacles. The specimen from Wijde bay (PI. i, fig. 11) showed a neomorphose (Carl- 

 gren 1904 p. 458). The oral disc is small, the actinopharynx as usual short. Siphonoglyphe ? 



Anatomical decription: The apertures of the physa are surrounded by circular muscles. At 

 the aperture in the mesogloea there is an annular wall of the epitheHum (whether of the ectoderm or of the 

 endoderm I cannot decide, the epithelium not being well preserved). This wall probably forms a movable stop- 



Textfigs. 50 — 51. 



Edwardsia vitrea. 



Section of a central aperture in 



the physa fig. 50 through the 



middle part fig. 51 through the 



rim. cm. circular muscles. 



Fig- 50- 



Fig- 51- 



ping, differently located according to the different state of concentration of the physa. In the Wij de-specimen 

 the waU turned towards the ectoderm, (textfigs. 50, 51), while in E. vegae (compare this species) it turned in- 

 wards. The wall is almost exclusively composed of elongated cells with large nuclei. The nemathybomes of 

 the examined type-specimen are flat and, on account of the bad preservation, containing only a few whole 

 nematocysts, the greater part of which are shrivelled, and as the stinging thread is thrown out there is no 

 distinct limit between the capsule and the thread. The nematocysts in the nemathybomes of the other spec- 

 imens were numerous, excepting the badly preserved Wij de-specimen where I found only a few nematocysts. 

 In the following table I have set up the size of the nematocysts in the different tracts of the animal. It ought 

 to be mentioned that the nematocysts are measured only in sections of the type-specimen. The measures are 

 therefore a little uncertain. 



Habitat 



scapus 



capitulum 



tentacles 



actinopharynx 



Great fiord 



68°2i'N (typesp.) 

 East-Greenland . . . 

 Wijde bay 



36—38 X 3.5 ,u 



about 38 

 37—42 X 3—3-5 

 34—38 X 3 



14 17 X 2 U 



14 17 X 2 



10 12 



24—29 X 2.5—3.5 U 



17—29 X 2.5—3.5 

 19—25 



38—51 X 3.5 ^( 

 36—53 X 3 



36—48 X 3-5 

 31—36 X 3 



17- 

 20- 



-22 1.1 

 -24 X 2.5 



In the specimen from Wijde bay I found only 2 nematocysts in the maceration preparation of the 

 nemathybomes, and in the specimen from Great Islet none, (as the parietal muscles of the latter are very strong 

 it is, however, probable that we have to do with E. vitrea). 



The periderm of the scapus is very thin and only a little incrusted. The nematocysts of the capitular 

 ectoderm are rather numerous, in the tentacles very numerous. The spirocysts of the tentacles obtain a size 



