146 Dublin Microscopical Club. 



the surface elevated into a Bumber (say probably ten or twelve) of 

 large hemispherical prominences ; thus the whole presented a very 

 broadly undulate ovitline. The cell-wall was thick, destitute of any 

 processes beyond the somewhat tall rounded prominences, as men- 

 tioned. The chlorophyll-contents dense and remaining of a bright 

 green. The identification of this pretty object as the zygospore of 

 the species mentioned rested upon the presence of a pair of empty 

 semicells, seemingly involved with it, and in just the position they 

 ought to assume if they really were the halves of one of the parent- 

 cells ; of course this assumption would have been enormously forti- 

 fied, if not indeed absolutely determined, had the empty semicells 

 of another parent-cell been found in a corresponding position. At 

 any rate, there could be but little doubt that this really was a 

 spore 5 and if the assumption as to its identity be correct, this would 

 seem to be the first record of the zygospore of that very common 

 species. Indeed it is rather curious how rarely some of the common 

 species of Besmidiece are met with conjugated, though others, indeed, 

 are frequently so encountered. The present zygospore has little 

 resemblance to any other, and at least could not be mistaken seem- 

 ingly for any described. Perhaps of all forms known it had most 

 resemblance to that of Penium phymatosporum, a not uncommon 

 species, of which, however, Mr. Archer had only once seen the 

 zygospore ; but, as might be expected from the relative size of the 

 species, the present zygospore is far smaller, and, though seem- 

 ingly elongate, is not subquadrate and compressed ; it is, as men- 

 tioned, in general form elliptic, and might be described as broadly 

 undulato-ovate. It has a certain resemblance, too, to the zygospore 

 of one at least of three common forms, confused under the name 

 Cosmarium margaritiferum, which, however, is greatly larger, 

 spherical, and its hemispherical prominences, in proportion to the 

 bulk of the total mass of the zygospore, not nearly so elevated. 



Gelatinous Alga from a Geyser-basin, Yellojvstone Park, Wyo- 

 ming. — Mr. G. F. Fitzgerald exhibited some morsels of a gelatinous 

 growth which he had found in the " Prismatic Pool " in the middle 

 of a Geyser-basin, Yellowstone Park, Wyoming, United States. 

 The mass from which he had taken the specimens grew to a distance 

 of about 5 or 6 feet nearly all round the edge of the pool, which was 

 about 30 yards in diameter. The water of the pool overflowed its edge 

 almost throughout, and it was in this overflow water that the jeUy- 

 like substance grew. The temperatui-e of the water was from 100° 

 to 120° Eahr. It grew on what appeared to be a flat tufia rock, depo- 

 sited out of the water of the pool, and covered it very uniformly to a 

 depth of about an inch to an inch and a half. Its upper surface 

 was gomewhat lumpy, very much like the thick moss that grows in 

 cushions on the tops of walls, when the cushions get close enough to 

 make a continuous surface. The upper surface was bright red, 

 but below it was a nearly clear jelly of about the consistency 



