ACTINIARIA 



" Edwardsia-mesenteries." In connection with the appearance of the tentacles these couples arise much 

 nearer to the lateral "Edwardsia-mesenteries" than it is otherwise commonly the case in the Actiniaria. 

 An older larva, sectioned in series, shows no filaments on the 6th couple and weak filaments on the 5th couple; 

 the filaments of the dorsal directive mesenteries were a little longer than those of the 5th couple; the ventro- 

 lateral "Edwardsia-mesenteries" were provided with the longer filaments; the dorso-lateral "Edwardsia- 

 mesenteries" had a little stronger filaments than the dorsal directives. The length of the filaments of the 

 ventral directives was about equal to that of the dorso-lateral "Edwardsia-mesenteries", but the former 

 filaments reach about as far down as those of the ventro-lateral "Edwardsia-mesenteries." 



The abnormally developed specimen with only 10 tentacles, of which I give a transverse-section 

 through the region of the actinopharynx (textfig. 134), had only 10 mesenteries. On one side of the direc- 

 tive plane the mesenteries were typically developed, on the opposite side one pair was totally missing. The 

 mesenteries marked with x are provided with weaker filaments than the other mesenteries. The strongly 

 ciliated boundary streak between the siphonoglyphe and the actinopharynx, occurring in adult specimens, 

 is not distinctly differentiated here. 



Peachia boekii (Dan. & Koren.) Hadd. 



PI. i. Fig. 30. 



Siphonactinia Boekii n. sp. Danielssen and Koren 1856, p. 88, PI. 12, figs. 4 6. 



Dan. & Kor., Milne-Edwards 1857, P- 2 3^- Andres 1883, p. 320, fig. 8. 

 Peachia (Dan. & Kor.), Haddon 1887, p. 475. Me. Murrich 1915, p. 969. 



Diagnosis: The nematocysts in the column 14 17 X (1,5) 2 p, in the tentacles 19 29 X 2 2,5 ft, 

 in the actinopharynx 24 26 X 3,5 4 (t. The spirocysts of the tentacles 14 X 1,5 26 X 2,5 //. Longitudinal 

 muscles of the tentacles ordinarily developed. Conchula with 3 rectangular, large, flat lobes, more or less 

 pedunculate, according to the state of contraction. Longitudinal pennons very strong with very numerous, 

 high and palisade-like, sparsely ramificated folds. Parietal muscles on the pennon-side strong with numerous, 

 comparatively high folds, only slightly ramificated or not at all so; on the opposite side weak, consisting 

 of few, rather high folds, not expanded upon the column. Oral and marginal stomata present. 



Colour: Column yellowish-brown with scattered brown spots. Tentacles brownish-yellow with 

 brownish-red annuli. Conchula shining like mother of pearl (Danielssen and Koren). 



Dimensions: Length of the body 2,5 cm, that of the tentacles I cm. Length of the conchula 0,9 cm 

 (Koren & Danielssen). On the preserved type-specimen the length of the tentacles was only 0,3 cm. 



Occurrence: Norway, Hardanger fiord 80 100 fms. (Koren & Danielssen). According, to Grieg 

 the type-specimen was dredged at Utne, at a depth of 376 fms. 



Exterior aspect: The column is cylindrical. The only preserved specimen I have seen is furnished 

 with longitudinal and transversal furrows, of which the latter have certainly arisen by the contraction of the 

 animal. I have not observed any elevations of the ectoderm in form of papillae. The number of tentacles 

 is 12. They are short, conical, sometimes a little longitudinally sulcated, probably in connection with the 

 state of contraction, and, according to Danielssen, arranged in a single cycle. Probably there may, how- 



The Ingolf-Expedition. V. 9. M 



