ACTINEARIA 



119 



there are traces of papillae. Fig. 5, PI. 4 represents a section through a part of the scapus, stained with car- 

 min of borax. The ectoderm is high in the papillae and unaltered, or possibly only a little transformed. From 

 the mesogloea off-shoots project, staining more intensely than the mesogloea itself (in the figure dark). On 

 some folds of the ectoderm these off-shoots are transversely sectioned, in wliich case they show a circular 

 arrangement. Though these paiDillae differ in structure from the typical papillae, I think that we also here 

 have to do with " Halcampa-psipillae" . Unfortunately I have only a few sections which are even more than 

 20 3'ears old, and it has been impossible to make new preparations as only very little of the ectoderm of the 

 scapus remains. For these reasons I cannot with certainty judge of the structure. It is possible that the sec- 

 tion has Jiit the edge of the papillae obliquely, so that the ectoderm above the papillae does not belong to 

 these latter; tliis is, however, not likely. Perhaps the structure of the papillae may be interpreted thus, that 

 the primitive papillae have been lost, so that of the cliitinized ectoderm-cells, only the off-shoots, which 

 are dark in the figure, have laeen left and the ectoderm has then regenerated to its full height. 



Halcampa duodecimcirrata M. Sars. 



PI. 4. Fig. 8. 



Edwardsia duodecimcirrata n. sp. Sars, 1S51, p. 142. 



— — Sars, Danielssen and Koren, 1856, p. 87. Danielssen, 1861, p. 45, I^iitken, 



1861, p. 196. Meyer and Mobius, 1863, p. 70, PI. 3, figs. A-D. Andresi88o 



P- 137- 

 Edwardsia Chrysanthellmn Peach., Mobius, 1S73, p. 100 (pro parte). 

 Halcampa — — Schulze, 1875, p. 121, 140. Haddon, 1886, p. 5, 1887, p. 478, 1889, 



P- 335 (pro parte). 

 Edwardsia liitkeni n. n. Andres, 1883, p. 308. 

 Halcampa farinacca Verr., Andres, 1883, p. 314 (pro parte). 



— duodecimcirrata Sars, Carlgren, 1893, p. 38, PI. 5, figs. 1—5, PI. 6, figs. 1—2, textfigs. 6, 7. 



Diagnosis: Physa ampullaceous, capable of almost complete involution, with small elevations, 

 perforated by 9 ( — 13?) apertures, one central and the others arranged in a circle around the central one. 

 Nematocysts of the scapus 10—12 X almost i ji, those of the capitulum 11— 17 X 1—1,5 H. those of the 

 tentacles about 12 X i /i. Spirocysts of the capitulum 14—19 X 1,5—2 /i, those of the tentacles 14—19 X 

 almost I— I II. Tentacles 8—12. Nematocysts of the actinopharynx 27—34 X 3.5—4 1^. "f^en narrower in 

 the distal end and with discernible basal part to the spiral thread. Perfect mesenteries 8—12. A more or less 

 perfect cycle of the second order present. Longitudinal pennons of the mesenteries with comparatively few 

 folds, 8—16 or a little more, only sUghtly branched. Parietal muscles and the nmscles of the imperfect me- 

 senteries weak, of about the same appearance. Expansion of the parietal mucsles on the colunm consider- 

 able. 8 to 10 (12?) perfect mesenteries fertile. 



Colour: Physa uncoloured, with small white spots. Scapus and capitulum pale flesh-coloured, the 

 latter often pale brownish-red, especially in the distal part, and often provided with 8—12 white longitu- 



