60 PROCEEDINGS OF SOCIETIES. 
one nor the other that he'had before him. It is possible that 
some of these smooth green bodies may have originated from the 
Penium, and never had a spinous coat developed. In a small 
form of Mesocarpus (which, not being conjugated, could not be 
identified) Mr. Archer had lately seen a number of minute stellate 
bodies (“asteridia”’) similar to those not infrequently seen in — 
Spirogyra, but with fewer and longer spines. But what makes 
that circumstance more especially worth noticing is that he had 
observed the slipping out of the smooth inner cell from the spinous 
outer coat by a rent, and this taking place still within the joint 
of the Mesocarpus ; he had not, however, noticed any evidence of 
any further growth or of a self-division. Be, then, the nature of 
these curious bodies in the Penium, in the Mesocarpus, or the 
more common similar growths in Spirogyra, what it may, it is at 
least highly probable that they are all analogous structures, and, 
in our present want of knowledge as to their true nature, they 
must remain “ asteridia.”’ 
Mr. Archer likewise exhibited a Cylindrocystis (Menegh.) as 
yet undescribed, and for the purpose of comparison and contrast 
placed side by side therewith, under other microscopes, specimens 
of Cylindrocystis Brébissonti (Menegh.) and of Cylindrocystis 
erassa (De Bary), when the absolute distinctness of all three spe- 
cies was readily apparent; and not only was their distinctness 
striking when viewed microscopically,but the difference in their ap- 
pearance in the mass to the unassisted eye was abundantly evident. 
The present plant Mr. Archer had as yet seen only in one locality, 
near Lough Bray, and there in several pools he had noticed it for 
three years past, but he regretted that, although he had annually 
taken specimens, he had not as yet been fortunate in finding 
this species conjugated. This plant formed a red stratum at the 
peaty bottom of the shallow pools, of some two or three inches in 
depth. It was greatly narrower and greatly longer than O. Bré- 
bissoniz, the ends truncate, and a microscopical examination 
showed that its red colour was due to the tint of the cell-wall, and 
not to that of its contents. In this year’s gathering it was mixed 
in some pools with C. Brébissonii, but these two very distinct plants 
side by side maintained their own characteristics absolutely. When 
Cleve’s name, Pentwm rufescens, for a new species (in ‘ Ofversigt 
af Kong]. Vetenskaps-Akademiens Férhandlingar,’ 1863, p. 493) 
first caught his eye, Mr. Archer imagined that the red colour 
rendered it likely that these two plants were the same, but an 
examination of the description and figure sets the point at rest— 
they are absolutely distinct, and could never be mistaken the one 
for the other ; besides, Cleve admits the genus Cylindrocystis as 
distinct from Penium, thus precluding the likelihood of his de- 
scribing the plant now exhibited (if, indeed, he had found it) under 
the latter genus. 
Captain F. W. Hutton then brought under the notice of the 
