22 CERIANTHARIA. 



Genus Ceriantheopsis nov. gen. Diagnosis see Section III. 



The only known species is 

 C. americanus (Verr.) PI. 5, fig. i 6. 



Agassiz, 1859, p. 24. 



Cerianthus americanus Verr ill, 1862, p. 32. 



Verrill, 1863, p. 56. 

 Verr. Andres, 1883, p. 560. 



Me. Murrich, 1890, p. 134. 

 Parker, 1910, p. 756, fig. 21. 

 Me. Murrich, 1910, p. 16, fig. IV, PI. i, fig. 14. 

 Pax, 1910, p. 167. 



Diagnosis: Large size with about 100 125 marginal tentacles and about as many labial tentacles. 

 The marginal tentacle* very long. Arrangement of tentacles: marginal tentacles in 4 or possibly only 



3 cycles 



2(dt)4,3, 

 3 



4,2,3, 

 3 



4, 2, 3, i 



etc. 



and labial tentacles in 4 cycles 2 (dt) 4, i, 3 4, 2, 3, 2 j 4, 3, i, 2 



4, 3, i, 2 ] etc. Stomatodaeum small with attachments for only 4 mesenteries. Hyposulcus absent, hemi- 

 sulci rather long. The directive mesenteries rather short with no development of ciliated tract. Proto- 

 mesenteries 2 fertile, reaching to the aboral part of the animal with well developed craspedonemes, 

 and narrow prolonged cnido-glandular tract resting upon a process. Protomesenteries 3 short with 

 well developed craspedonemes and cnido-glandular tract region. Arrangement of metamesenteries 

 mBMb in clearly marked quartettes. M agree in structure with pro torn esenteries 2, are fertile, long, 

 the longest reach to the aboral pole, increasing in length towards the multiplication chamber, though 

 with breaks in one or two places (at the 3rd, 5th and possibly the 7th quartette); m fertile, short, the 

 free border twice as long as the free part of B and 6, with rather larger cnido-glandular tract than 

 M's, in other respects like M. B and b sterile, very short, with longer cnido-glandular tract region 

 and shorter craspedoneme region. This is especially the case with b. The region of the ciliated tracts 

 is constructed on type 2 in the oral part. The region of the craspedia is long in M and protomesen- 

 teries 2, shorter in m. In protomesenteries 2 and the longest metamesenteries M the craspedia in the 

 most aboral part form a small craspedoneme, which contains very numerous thick-walled nematocysts. 

 Occurrence: Beaufort N. Carolina. Copenhagen Museum i ex.; several examples from Director 

 Aller. Distribution according to Parker (1900): from Cape Cod to Florida. 



Dimensions. Length 60 70 cm., disc of nearly 4 cm. Verrill. Length in the largest specimens 

 20 cm., diameter through the middle 1-5 2 cm., the disc r8 2-5 cm. Length of outer tentacles 3'4cm. 

 of the labial tentacles r8 2-5 (Me. Murrich). The specimens I examined had a length of 7 8cm. 

 in their preserved state. 



Colour. "The color of the column is some shade of brown varying from pale chocolate-brown 

 to deep purplish brown. The upper part is always darker than the lower and in some cases the column 

 is marked with longitudinal lines of a lighter shade than the ground colour. The marginal ten- 

 tacles are of a paler brown than the column except the outermost, which are purplish blue. The 

 oral tentacles in all specimens I observed were pure white; Verrill on the other hand, describes 



