416 PROCEEDINGS OF SOCIETIES. 



pectinata. Dr. McNab proposed to call this form provisionally 

 Ahies Harry ana, after Mr. Harry J. Veitcli, the head of the firm 

 of Veitch and Sons, Chelsea. 



Film of vitreous Selenium, exhibited. — Mr. R. J. Moss exhibited a 

 transparent film of vitreous Selenium about j-g'oo" i'"* thickness, 

 and containing a depdritic mass of the same element in the crystal- 

 line form. He referred to the allotropism of Selenium, and stated 

 that this early stage of the transition from the vitreous to the 

 crystalline state had not hitherto been observed. 



JVew Cosmarium sp. exhibited. — Mr. Crowe showed a Cosmarium 

 gathered by him in the greatest purity and abundance in a pool 

 near Bangor, North Wales, which appeared to be un described. It 

 is of rather large size, granules fine and scattered, semicells in figure 

 resembling those of Cosni. biretum, but in end-view elliptic, the 

 lateral margins with a very slight median prominence (not with a 

 large rounded inflation at each side), Mr. Archer had forwarded 

 examples to Mr. Roy, of Aberdeen, and to Herr Nordstedt, of 

 Lund, with a view to gain the opinions of those observers. 



Cosmarium pseudomargaritiferum, Reinsch, ex herb. Heinseh, 

 exhibited ivith its zyrjospore, and note thereon. — Mr. Archer showed 

 authentic examples of Cosmarium pseudomargaritiferum, Reinsch, 

 showing the peculiar zygospore. This form, though smaller in 

 dimensions, appeared the same as Cosmarium Portianum, Archer. 

 Professor Reinsch describes the zygospore as smooth — certainly it 

 is not spinous — but it is deeply sci'obiculate, a character vvhich that 

 observer does not record. In this it seems to resemble no other zygo- 

 spore save that of the otherwise dissimilar X.anthidium armatum, 

 and hence, in the genus Cosmarium, it is (as yet) unique. The 

 zygospore of Cosmariu77i margaritiferum, or better Cosm. reniforme 

 {Cosm. margaritiferum, reniforme, Ralfs) is much larger, 

 very thick-walled and absolutely smooth (not scrobiculate), whilst 

 that of Cosm. margaritiferum proper is large, thick-walled, and 

 covered by thickened subhemispherical hyaline prominences (com- 

 parable to " bull's eyes" in glass) ; thus the three forms are distinct 

 in every particular, and the suggested or implied close affinity to 

 one or other of the other species in question conve3-ed by the name 

 "pseudomargaritiferum" appears altogether unjustifiable. 



JEurotium herbariorum from tan-bed exhibited. — Mr. Greenwood 

 Pim exhibited specimens of a Fungus which had appeared in great 

 abundance on a tan-bed in his garden, so numerous as to give quite 

 a rusty tinge to the tan ; further investigation showed they were 

 immature conceptacles of Eurotium herbariorum, Lv. 



^th June, 1876. 



Diatomaceous forms, with a new species of Colletonema, from 

 sub-fossil material forms along icith remains of Megaceros. — 

 Rev. Eugene O'Meara presented a slide containing Diatomaceous 

 forms found in a subfossil material from Ballybetagh, under the 

 stratum in which were embedded numerous remains of the extinct 



