2 HiCKSON, Specimen of Osteocella septentrionalis {Gray). 



The colour was pale pink, foot and stem paler than 

 the part bearing the polyps. 



The polyps emitted a bright blue-green colour on 

 being irritated. The whole object was covered with a 

 thick slime. 



The total length was 6 feet lo inches, i.e., about two 

 metres. The circumference of the middle region of the 

 rachis was about i| inch = 47 mm., of the upper part of 

 the stalk if inch = 35 mm., and of the bulbous enlargement 

 of the stalk about 2| inch = 74 mm." 



The axis. A complete description of the axis cannot 

 be given, owing to the imperfect condition of the specimen, 

 but I have compared some fragments of it with the 

 complete type specimen of Osteocella septentrionalis in 

 the British Museum. 



The length of the type specimen is 64 inches, and the 

 greatest diameter is 5 mm. The diameter of the axis in 

 the middle region of the stalk of the specimen sent to 

 me is 7 mm. Whether this represents or does not the 

 greatest diameter of the axis when it was complete I 

 cannot say, but judging from this fact, it seems to me 

 probable that the axis of this specimen was longer than 

 that of the type. In structure it resembles the type 

 specimen very closely. It is very hard and in section 

 shows concentric growth rings. Its structure appears to 

 be uniform in the respect that there is no dark central 

 core, similar to that figured by Kolliker (7} in the axis of 

 Virgularia. 



The comparison of the two axes leaves no reasonable 

 doubt that our specimen belongs to the same genus as the 

 type specimen of Osteocella septentrionalis in the British 

 Museum. 



The autozooids are arranged in close set pinnae on 

 both sides of the rachis. There are about 12 autozooids 



