CERIANTHARIA. 



II 



The cnido-glandular tract contains a multitude of small finely granular gland cells and very 

 numerous mucus cells, and thus does not present the typical appearance found in other Ceriantharia 

 which I have investigated (Fig. 6, PI. I). The thick-walled nematocysts which are not marked in 

 the figure are 29—31// long and 7// broad. Spirocysts occur very seldom, as also the long nematocysts 

 above mentioned. 



The musculature of the mesenteries is similar to that of Cerianlhus lloydu\ on the side of 

 the mesenteries remote from the directives are found longitudinal 

 muscles, on the near side, transverse ones. As for the directive me- 

 senteries their musculature has not been investigated by me. (Text- 

 fig. 2, PI. I, Fig. 2). 



The mesogloea of the mesenteries is feeble as a rule and con- 

 tains very thinly scattered though large cells, which often occupy a 

 cyst-like space; in the craspedoneme region they are rather more 

 numerous. 



The endoderm is strong and provided with numerous remark- 

 ably homogeneous gland cells. 



The specimen examined was hermaphrodite with well devel- 

 oped ova and spermatozoa. 



Systematic remarks. In my paper in Nordisches Plankton (1906) 

 I assumed that this form by reason of the large tentacles was the 

 fully grown form of Arachnactis albida. This is not the case, how- 

 ever, as the anatomical investigation sufficienth shews. On the other hand it is not unlikel)- that 

 Arachnactis albida is a larval form of Arachnanthus sarsi described below (compare this form). 



Textfig. 2. Pachycerianthtis multipli- 



calus. Portion of column, .stoniato- 



daeum and inesenterie.s. 



O 



Genus Cerianthus delle Chiaje. Diagncsis see Section III. 



Species Cerianthus lloydii Gosse. PL 3, PI 4, figs. 4-5 PI. 5, fig. 11. 



Edwardsia vestita (Forbes) Gosse, 1856, p. 73. 

 Cerianthus vievibranaceus (Gmel.) Gosse, 1858, p. 419. 

 Cerianthus lloydii n. sp. Gosse, 1859, p. 50. 



» » Gosse, i860, p. 268, PI. 6, fig. 8. 



» » Gosse. Andres, 1883, p. 346. 



» » » Pennington, 1885, p. 179. 



» » » Sars, 1861, p. 262. 



» » » (Koren) Daniels sen, 1877, p. 80, note PI. 4, figs. 8, 9. 



» » » Carlgren, 1893a Fig. i, 1893b, p. 120, fig. 39, 40, PI. 10 fig. i. 



» » » Hartlaub, 1894, p. 203. 



» » » E. van Beneden, 1898, p. 24, 25, fig. A, PI. i, figs. 1—4- 



