22 THE VOYAGE OF H.M.S, CHALLENGER. 



This species appears to differ in the form of its spicules from all hitherto described. 

 Habitat. — Stations 194 and 194a, off Banda ; depth, 200 and 360 fathoms ; bottom, 

 volcanic mud. 



5. Acanella simplex, Verrill (PI. IX. fig. 5). 



Acanella simplex, Verrill, BulL Mus. Comp. Zool., vol xi. p. 17. 



Axis slender, apparently unbranched, 1 mm. in diameter ; calcareous internodes 

 sulcated, solid, or in the youngest internodes with a very minute central tube ; horny nodes 

 short. Polyps arranged in an alternate manner on the axis, prominent, about 5 mm. 

 distant on lower portion of the axis, with lesser intervals towards apex, more or less 

 cylindrical in shape, from 4 to 5 mm. in height and about 1 mm. broad. The coenench3Tna 

 on the axis is thin, but when in a perfect condition it is crowded with obtuse fusiform 

 spicules ; these are easily rubbed off. The base of the polyp is packed with larger and 

 more curved fusiform spicules, and the tentacles are stiffened with minute, echinated, 

 oblong spicules; from six to eight rather blunt fusiform spicules form a projecting fringe 

 around the imperfectly closed tentacles. 



This species was described by Verrill {loc. cit.) from two specimens, one taken in 334 

 fathoms, off Martinique, and the other in 399 fathoms off Barbados. It seems to belong 

 to Acanella, and it is quite possible that it is a feebly branching form, so that the 

 genus may not require to be emended so as to include simple stemmed forms. The solid 

 calcareous joints will serve to distinguish this form from any of the species of Ceratoisis. 



The long needle-shaped spicules on the polyp vary greatly in length from 3'5-0"5 ; 

 2 "0-0 "5 ; 1 •5-0*25 mm. Those on the coenenchyma and tentacles measure 0'5-0'09 ; 

 0-67-0-04; 0-4-0-06 ; 0-89-0-05 ; O'OG-O-OIS mm. 



Habitat. — Station 56, off Bermudas ; depth, 1675 fathoms; bottom, Coral mud. 



Genus 4. Bathygorgia, Perceval Wright. 

 Bathygorgia, Perceval "Wright, Narr. ChaU. Exp., vol. i. p. 691, fig. 236. 

 Axis with long, irregularly curved, and somewhat square calcareous internodes and 

 small horny nodal joints. Coenenchyma of the axis thin ; but covered with oblong 

 warty spicules. Polyps large, uniserial, with non-retractile tentacles, body covered with 

 large, spiny, biclavate, and club-shaped spicules. 



Bathygorgia profunda, Perceval Wright (PI. VI. fig. 3 ; PI. Va. fig. 9). 



Bathygorgia profunda, Perceval Wright, Narr. Chall. Exp., vol i. p. 691, fig. 236. 

 The axis in the only specimen of this remarkable form, dredged during the cruise of 

 the Challenger, is evidently but a fragment ; it is about 6 cm. in length and 1 mm. in 



