264 Dr. J. E. Gray on Hyalonema Sieboldii. 



Mr. Gregory sent with this coral a very interesting speci- 

 men of Hyalonema Bieholdii, It is attached to a sponge 

 which shows on the surface the numerous circular and oblong 

 (this form being perhaps produced by compressing the open 

 mouths) oscula, surrounded by a slightly raised edge, which are 

 figured in Professor Schultze's plate. The presence of these 

 oscules shows that the prominences in the bark cannot be " the 

 oscule" as Dr. Bowerbank supposes. 



The coil is very short, very thick, and formed of a large 

 number of short spicules. These spicules, though short, are 

 complete ; for they taper at the tip, and exhibit the usual ap- 

 pearance of perfect spicules ; otherwise it might have been 

 supposed that this was only the base of a longer coil. The 

 coil is a full inch in circumference at the base, and spread out 

 towards the end. It has unfortunately been entirely deprived 

 of its bark, except just where it emerges from the sponge, 

 where there is a narrow imperfect ring of the bark, with 

 small-sized circular prominences, being the contracted po- 

 lypes, which are raised considerably above the surface, and 

 have a small central impression. The coil is about 8 inches 

 long; but one or two of the spicules are nearly one inch 

 longer. 



Every specimen that I see of this production more and more 

 confirms my first idea that the coil and bark constitute a coral 

 which is connected with a parasitic sponge. 



XXXII. — On a new Free Form q/* Hyalonema Sieboldii, and 

 its manner of growth. By Dr. J. E. Geay, F.R.S., 

 V.P.Z.S., F.L.S. 



Mr. W. Cutter has most kindly sent to me for examina- 

 tion a series of seventeen specimens of Hyalonema Sieholdiij 

 which he had just received from Japan. They are all in good 

 condition, better than most specimens when they arrive. The 

 bark in all but one is decidedly in its natural state ; this, on 

 the other hand, certainly has been entirely stripped of its 

 bark, and fresh bark recently stripped from some other speci- 

 men has been artificially put on to it ; it would almost appear 

 as if the coil of two specimens had been twisted together into 

 one. 



The series shows two very distinct varieties — one the kind 

 hitherto known, which is found affixed to a sponge, and the 

 other a free form of the coral, which is covered with bark 

 to the very base of the coil. Of the sixteen specimens in their 

 natural state, nine belong to the first, and six to the latter or 

 free variety. 



