316 PROCEEDINGS OF SOCIETIES. 



and each of the free masses, it will be borne in mind, is alao 

 attached by similar prolongations to the five masses already below 

 them, and will be equally attached to the five masses that will be 

 formed above them. When these masses, which are the '' siphons " 

 of the algologist, reach adult age, a delicate cellulose membrane 

 forms around each, and between these and the common investing 

 cell-wall there is sometimes a well-marked interval, which is in 

 some species filled up by cellules. No true articulation at this 

 stage exists in the stem ; it only occurs later in life, and iu a 

 manner seemingly as yet undescribed. 



Structure of Spines of Toxopneustes variegatus, Lamk. — Mr. 

 Mackintosh exhibited a cross section of the spine of Toxopneustes 

 variegatus, Lamk., which showed two cycles of solid wedges, 

 the inner very small, the outer much larger, globular in contour, 

 and connected to each other by single short bars perforated with 

 a few delicate tubes. 



Magnetic Particles occurring in Arctic Ice-chi.st. — \)v. !Mos8, 

 H.N., exhibited a sample of Arctic Ice-dust, and showed inter- 

 mingled magnetic particles under the microscope, calling atten- 

 tion to their movement under a magnet caused to move about 

 under the stage. 



An OsciUatoria from Australian Seas, occurrinrj in large quan- 

 tities. — Mr. Archer exhibited examples of an alj^a forwarded by 

 Professor Thiselton Dyer, an OsciUatoria from the surface of the 

 Australian Seas, often forming large masses and thrown ashore. 

 Locally, this was popularly called Whale-Spawn, and its nature 

 misunderstood, being accounted there as somehow a kind of 

 slough or exuvium from certain polypes. Whether originally 

 colourless or whether by drying it had become bleached was un- 

 certain. The cells were unequal in size. In the mass this ]iro- 

 duction is described as giving off a very foul smell ; this however, 

 more than probably, may be only when it is undergoing decom- 

 position in the sun on the beach. Perhaps the most remarkable 

 circumstance connected with it was the vast quantity in which, 

 at certain seasons, it would appear io occur. 



Polariscopic aspect of Artijicial Gems. — Mr. Grubb showed 

 the polariscopic appearance of certain of the arlilicial gems 

 (sapphire, &c.) now being manufactured by M. Feble of Paris, 

 in which respect they are not to distinguished from genuine 

 stones. 



" Japanese Isinglass.^' — Mr. Draper showed sections of the so- 

 called Japanese Isuiglass, and stated he had arrived at the same 

 conclusion as Professor Mr. Nab, that this was in reality M>:ne 

 form of starch. 



Navieula Mossiana, n.s., O.'M., exhibited. — Rev. E. O'Meara 

 showed a slide from material dredged from a depth of seven 

 fathoms in Discovery Pay 81° -1-3' N., for which he was indebted 

 to the kindness of Dr.'Moss, R.N., late of II.M.S. "Alert." 

 Amongst the forms contained was one belonging to the ccnua 

 Navieula, which he considered not hilhcrto named, and proposed 



