ACTINIARIA 



I 2 //, partly 24 34 X 2 2.5 /*. Longitudinal muscle-pennons rather strong with folds of ordinary 

 height and a little branched, in numbers less than 20, the stronger folds in the outer part, shortened inwards, 

 and in the innermost part one or two longer folds. Outer lamellar part of the mesenteries attached to the 

 pennon rather close by the centre. Parietal muscles comparatively weak, dichotomously branched. Expan- 

 sion of the parietal muscles on the column considerable. 



Colour. Scapus dirty-grey to ochreous-coloured. 



Dimensions. In extended state the largest specimen with 20 tentacles (from little Belt) was 

 2.4 cm high and 0.2 cm broad. The largest, a little contracted, specimen was 2 cm long and 0.25 cm broad. 



Occurrence. Cattegat (Petersen), Torboskar-Skagen 19 22 fms. (Gunhild-Exp. 1878), Little 

 Middelgrund 10 fms. (Gunhild-Exp. 1878), Laholm bay 10 12 fms. (Gunhild-Exp. 1878), Great Belt 

 Winther), Little Belt (Mortensen 1900), 7 24 fms. (Schiodte), off Lyngs Odde 10 fms. (Mortensen 

 1912), Samso Belt (Winther). 



The Sound (Holier, Liitken). Between Landskrona and Haken 17 21 m S. of Hven 17 26 m; 

 W. of Knahaken 23-25 m, W. of "Disken" 24 m ("Sven Nilsson" St. 27, 30, 42, 43 a, 52 c), S. of Hven 6 24 

 fhs. (Gunhild-Exp. 1878). 



Exterior aspect. The physa is of usual appearance. The scapus is provided with a rather well- 

 developed periderm. The nemathybomes are small, not visible to the naked eye and not protuberated on the 

 surface of the scapus. They are scattered, not as numerous and not as aggregate as in E. pallida, which 

 becomes evident by a comparison of the figs. 16 b, 17, p. 32. 



In surface preparations (textfig. 17) as well as in sections (textfig. 27) they show a different agroup- 

 ment. Sometimes two nemathybomes close by each other are seen in contracted specimens of E. danica 

 (textfig. 27) ; in shape they are, however, different from those of E. pallida. In order to control the arrangement 

 of the nemathybomes I have sectioned several specimens of both species, examined them in surface prepa- 

 rations and always found thorough differences in the agroupment of the nemathybomes. The tentacles are 

 of usual size and appearance. They vary considerably in number. In the smallest, extended specimen from 

 Little Belt (Mortensen 1912) there were only 12 tentacles (this specimen is, however, probably not fertile; 

 I have sectioned the lower part of it, but not found any reproductive organs) ; in 3 other sectioned fertile speci- 

 mens (from Samso Belt, Little Belt and the Sound St. 27) the number of tentacles was 14, 16 and 16. The 

 best, extended specimen (from Little Belt Mortensen 1912) with evolved tentacles had 20 tentacles. In 

 Edwardsia pallida I have observed only 16 tentacles. The oral disc and the actinopharynx are of usual appear- 

 ance. A weak, ventral siphonoglyphe is present. 



Anatomical description. The periderm of the scapus is rather well-developed, in the paler 

 specimens thinner. The nemathybomes are small and contain nematocysts of two different sizes, both a 

 little broader at the basal end. The large capsules were mostly very sparse, in some specimens I did not find 

 any in the maceration preparations; it is, however, possible that they are present also there. In the macera- 

 tion preparations of the specimens 4 and 5 (compare the table) I observed only some few capsules. They 

 always show a discernable basal part to the spiral thread what is also often the case with the smaller nema- 



