CERIANTHARIA. 



31 



Occurrence : Norway, Troiidhjeni fjord among branches of I^ophohelia and Paragorgia. 



» ^ ' Rodberg 50— icx)m., Aug. 1898, Arvidsson, R. M. 



» » » Skarnsund Indalbay, 100 — 200 m., Sept. 1898, Ostergren. 



R. M., U. M. 

 » » » Rissen, about 200 fathoms in Oculina colonies 31. 7. 1902. 



Svenander, R. M., T. M., U. M. 

 » » » Galgensesset. Rocky ground. On dead Oculina T. M. 



» ■ s without specified locality T. M. 



Diviensions. A couple of the largest preserved specimens measured: specimen i — 3-2 cm. in 

 length and 0-4 cm. in breadth. Specimen 2—3-6 cm. in length and 0-3 cm. in breadth. Marginal ten- 

 tacles 0'35 cm. long, labial tentacles 0-2 cm. 



Colour. According to Dr. Arvidsson's account. Body colourless, transparent, the oral part 

 very faintly flesh-coloured. Tentacles fainth' flesh-coloured. 



Exterior aspect. The body has the appearance characteristic of the Ceriantharia. There is 

 probably an aboral pore. 



The tentacles are comparatively short, conical, the labial tentacles distinctly shorter than the 

 marginal. The arrangement varies somewhat according to the age of the animal. In a small-sized 

 specimen with 20 marginal and 10 labial tentacles the arrangement was as follows. 



dt 



marginal tentacles i, 2 

 labial tentacles 



1,2,1,2 

 ,1,1,1 



3 older specimens shewed the following arrangement 



I, 2, 2, 1, 2, 2, I 

 1,1,0,0,0, 1, 1 



dt 



2, I, 2, I 

 I, I, I, 



2,1,2 



Sp. I. 26 marginal tentacles 3 

 16 labial tentacles 



1,3,2,3 



1, 3, 2, 3 { 1, 3, 4, 1, 4, 3, 1 3, 2- 3, ^ [ 3, 2, 3> i 3, 2, 3 

 1, 1, 1, 1 1 1, 1,0,0,0, 1, 1 , 1, 1, 1, 1 1 1, 1, I 



The tentacle arrangement of specimen 2 (with 30 marginal and 16 labial tentacles) agrees with that 



of sp. I. A third example shews some variation 



32 marginal tentacles 2, 3, i, 3 

 17 labial tentacles 



2, 3, 1, 3 

 1,1 



2,3,1,3 



dt 

 2, 3, 4, 1, 4, 3, 2 j 3, 1, 3, 2 ' 3, i. 3, 2 j 3, r, 3, 2 



I, I, o, o, o, I, I I I, I, I, I I I, I, I, 



which comes to an interchange of the ist and 2nd tentacle cycles. Which of the two is the typical 

 grouping is hard to say and can hardly be determined with certainty except from living subjects, as 

 the tentacles of the ist and 2nd cycles are very close together. The number of the marginal tentacles 

 will probably not exceed 34. Characteristic pomts are the great difference in the number of the 

 marginal and labial tentacles, and the arrangement of the marginal tentacles in several cycles of the 

 labial tentacles in one onl)'. 



The stomatodaeum is short, about Ve of the length of the bod\-, longitudinally furrowed, and 

 with special distinctness in the aboral part. Only the directive mesenteries are attached to this \ery 

 narrow siphonoglyph. The hyposulcus is extremely slight, as also the hemisulci. 



Anatomical description. 



The column shews the usual structure. The numerous nematocysts with much coiled thread 

 are comparatively short in relation to the breadth, and of 2 sizes 36— 43^ x 5—7/^; 24—26// x ■/ ft. 



