DUBLIN MICROSCOPICAL CLUB. 123 



June 19th, 1878. 



Gephyria Dyeriana, exhibited. — Eev. E. O'Meara exhibited a 

 specimen of Gephyria Dyeriana, a new species found by him \\\ 

 a gathering made by Mr. Moseley at Kerguelen's Laud, and de- 

 scribed by him (Mr. O'Meara) in ' Linu. Journ. Botany,' vol. xv, 

 p. 59, pi. i, fig. 10. 



Roestelia lacerata, exhibited. — Mr. Pim showed the fungus 

 Hoestelia lacerata found by him much diffused over a hawthorn- 

 hedge at Woodenbridge, Co. Wicklow. 



Cosmarium, n. s., very minute, with finely spinous Zygospore, 

 exhibited. — Mr. Archer showed examples of an extremely minute 

 and rather common little Cosmarium (to give an idea of its size, 

 scarcely so large as the well-known C. tinctum), of which, how- 

 ever, the zygospore was not before exhibited or recorded. This 

 little Cosmarium was characterised by a flatness of the top — 

 a small character on which to build a species, some might say — 

 but Mr. Archer thought one could hardly miss to know the species 

 for all that ; but further, it is the only one of the extremely 

 minute forms wath a spinous zygospore. The zygospore is 

 globular and beset with extremely minute fine and pointed spines, 

 lending thereto an almost hirsute appearance. This was the 

 third occasion on which Mr. Archer had taken this form con- 

 jugated. He would call it Cosmarium lasiosparum. 



Tttraspores in Polysiphonia. — Dr. E. Perceval Wright exhi- 

 bited mounted specimens, showing the difierent stages in the 

 evolution of the Tetraspores in Polysiphonia formosa. Their 

 point of origin would seem to be always between the central cell 

 and its surrounding cells (siphons). At the base of the central 

 cell a small portion of protoplasm is detached, this then soon 

 divides transversely, the lowermost morsel forms a very minute 

 table, while the uppermost assumes an oval form ; this latter 

 remains attached to the former by means of a little stalk of pro- 

 toplasm, which eventually supports the cell which originates the 

 tetraspores. These are formed by the division of the i)rotoplasm 

 of the cell formed out of the upper oval-shaped mass. It; divides 

 into four nearly equal portions ; these have no points of attach- 

 ment to each other. But in the process of growth these four 

 masses gradually arrange themselves after the very characteristic 

 method of these vegetative cells. 



July 20th, 1878. 



Cylindrocystis crassa and Mesotaenium violascens in company 

 from Co. Kerry, were shown by Dr. Moore. These algae are 

 widely diffused, yet scanty, and it is hard to get a good and pure 

 unmixed gathering. 



Chytridium with hacillar zoospores. — Mr. Archer showed a 

 Chytridiura on Eremosphcera viridis with zoospores caught during 

 egress. The point of interest was their very elongate or cylin- 

 drical figure, not, as seems usual, orbicular, or nearly so. With 



