203 



doubt these curious specimens were calculated to add to the puzzle, 

 but every little observation as to structure, however partial or 

 limited, might come in some day as useful in assisting to determine 

 the true state of the case as regards these pretty plants, and hence 

 the present examples, qucmtiim valeant, were so far worthy an 

 examination and record. Mr. Archer hoped some time to be able 

 to revert to these and other specimens in this group more at large. 



Mr. Robinson brought for exhibition " Reade's ]?rism," and very 

 satisfactorily showed various Fleurosijmata by its aid. 



Mr. Archer showed examples in considerable abundance of a new 

 and very minute form of Spirotcenia. This is exceedingly slender, 

 being, however, long as compared with the diameter ; the cells some- 

 what curved or arched, shghtly tapering, ends truncate, the endo- 

 chrome forming a single spiral reaching from end to end of the cavity, 

 self-division transverse. As regards the width of the cells, this 

 species is the most minute known, though S. parvula (Arch.) is 

 shorter in length. The only form this could well be mistaken for 

 would most likely be AnJcistrodesmusfalcaius, with which it pretty 

 nearly agrees in size ; but besides the spiral endochrome, the cells 

 being blunt, not acute, at the apices, is a character striking the eye 

 at first glance. Mr. Archer hoped to figure and describe this form 

 more at large on a future occasion, naming it ^S*. tenerrima. 



Dr. E. Perceval Wright exhibited portions of the spicular 

 skeleton of Aj)hrocalUstes Bocagei, from deep-sea dredgings off the 

 south-west coast of Ireland. For these he was indebted to the 

 kindness of Professor AVyville Thomson, who informed him that 

 some of the specimens were found living. 



IQth December, 1869. 



Dr. John Barker showed various objects {ConocJiihis volvox, &c. 

 &c.) viewed by aid of the new parabolic condenser, on the new 

 principle contrived by him, by interposition of a stratum of water 

 (or oil) between the Jlaf top of the condenser and the slide. The 

 objects now exhibited were beautifully seen on a very dark field, and 

 well illuminated. Dr. Barker stated he was pursuing some investi- 

 gations and experiments with a view to the adaptation of the prin- 

 ciple to the higher powers, and hoped again to lay further results 

 before the Club. 



Dr. Moore showed a production sent to him from the County 

 Wexford, found in a dried-up pool, and which, as seen in the hand, 

 had all the appearance of so much cotton wadding, being quite white 

 and hardly at all distinguishable therefrom ; it had, indeed, occurred 

 in such quantity, and was so like in appearance and feel to cotton 

 wadding, that a mass of it had been employed to pack plate on its 

 transit to Dublin. On being however placed under the microscope, 

 it was found to be made up of the dried remains of a species of 

 (Edogonium felted together in a very dense manner, and, in place 

 of appearing white, as seen by the unassisted eye, it presented a 

 certain amount of its natural green appeai'ance, though the cell- 

 contents were in most cases, of course, much contracted, and their 



