ACTINIARIA 



smaller, 1722 X 3 it, partly larger, 26 29 X 4 ft. In the papillae which show the same structure as those 

 of Halcampa, the ectoderm is low, and the cells of another structure than that of the other parts (compare 

 the family Halcampidae). The scapus hardly seems to form a regular cuticle, but by the secretion of the'gland- 

 cells particles of mud and foreign bodies are glued together so as to form a thin membrane, covering he 

 scapus (compare above!). The mesogloea is stratified, of ordinary thickness and sometimes tapering into 

 papilliform off -shoots. When the scapus is expanded the "//a/caw^>a-papillae" are not distinct, and their 

 position is only indicated by their structure which is different from that of the other parts of the scapus. 

 The scapus-endoderm is of about the same thickness as that of the ectoderm. The capitular ectoderm is 

 high, higher than the mesogloea and contains numerous nematocysts, partly larger 24 X 2,5 n, partly smaller 

 about 14 X 2 ft. On maceration-preparations of the capitulum I have also observed 

 spirocysts. As, however, I did not find any spirocysts on sections through the same 

 region, it is probable that the spirocysts belonged to the tentacles, and were stuck to /- 

 the capitulum which is invaginated with the tentacles. The mesogloea of the capitu- 

 lum is more fully developed in the middle of the compartments than on their sides. 



\>i _-/ ' s 



The ectoderm of the tentacles contains numerous nematocysts, 24 /i long and 2 ;i 

 broad, and very numerous spirocysts of a length of unto 28 40 ft. The high ecto- 

 derm of the actinopharynx is furnished with numerous nematocysts, partly larger, 

 about 31 36 x 3 /it, partly smaller, 20 22 X 2 //. 



The 8 imperfect mesenteries are short and thick. The longitudinal muscle-pen- 

 nons on the 8 perfect "Edwardsia mesenteries" appear rather elongated on trans- 

 verse-sections in the reproductive region (textfig. 86) and with about 25 to 30 folds. 

 These latter are rather much ramificated, especially in the outer parts. The more cen- 

 tral folds are of almost equal height and considerably lower than the folds nearer to 

 the outside. In the region of the ciliated streaks and off the actinopharynx the folds 



are lower and more concentrated. The parietal muscles are well developed (textfig. 86) a 



arenarta. Transverse sec- 



with several folds of fan-shaped appearance on each side of the main-lamella of tion of mesentery, 

 the mesogloea. The parietal muscles are rather considerably expanded on the column, but they do not 

 reach as far as -the parietal muscle-pennons extend. The ciliated streaks, the streaks between these lat- 

 ter, and the middle streak are well developed. In the lower parts of the filaments there are also boundary 

 streaks, furnished with vacuoles along their outside. The animal is dioecious. Two specimens, examined 

 more in detail, were males (Textfig. 86 te: testes). 



The anatomical description of this species is principally based on the specimens from the Gunhild- 

 Kxpedition. 



Paraedwardsia sarsii (Diib. & Koren) Carlgr. 



PI. I. I'igs. 8, 9. PI. 4. l-'iR. 7. 



ILccythia brcvicornis n. sp. M. Sars 1829, p. 27, PL i, fig. 10. 



Sars, Sars 1833, p. 226, PL 10, fig. 5, 1835, p. 3, Ehrenberg 1834, p. 73. 

 Kilwardsia sarsii Diib. Diiben and Koren 1847, p. 267. 



