142 Dublin Microscopical Club. 
envelopes of Phycochromaceous Alge, as frequently occurs on damp 
rocks in subalpine spots, but here rather unexpectedly showing 
imbedded certain Cosmaria. Prominent amongst these was the 
large and on the whole decidedly rare rock-form Cosmarium plica- 
ium, Reinsch, forma majus. Doubtless under the name Cosmarium 
plicatum, Reinsch had in view two very distinct things, both indeed 
rare, although the smaller one is somewhat more frequently met 
with and usually in somewhat greater numbers than the “ forma 
majus.” This, the present one, occurs both in Ireland and Scotland, 
specimens from those wide-apart sources being absolutely identical. 
Cosmarium acanthophorum, Nordstedt, exhibited to show that the 
form appertains rather to Xanthidium.—Mr. Archer showed the so- 
called Cosmarium acanthophorum, Nordstedt, also Xanthidium Nord- 
stedti, Reinsch, showing how closely they approached one another, 
and expressing some wonder that Nordstedt should relegate such a 
form to Cosmarium at all, his name seeming to involve what might 
be almost regarded as a contradiction in terms as is expressed in the 
designation ‘‘ spine-bearing Cosmarium.” 
Ammodiscus Scharmanni new to Ireland.—Mr. Balkwill, amongst 
many beautifully mounted Foraminifera, showed Ammodiscus 
Scharmannt, new to the Dublin fauna. 
Air-bubbles in Water-cavities of Quartz—Prof. Hartley showed 
some good and striking examples of air-bubbles in water-cayities of 
quartz. 
April 19, 1883. 
Specimens of Torrubia (Cordyceps) exhibited—Mr. Pim showed 
one of the strange group of Spheriaceous Fungi parasitic on insects, 
formerly called Cordyceps, now referred to Torrubia. The speci- 
mens were from the herbarium of Trinity College, and were identi- 
fied by the Rev. M. J. Berkeley as Torrubia (Cordyceps) Gunme, 
natives of Van Diemen’s Land, whence they had been sent to the 
late Professor Harvey. The sections showed very long slender 
sporidia having a seemingly chain-like structure, or like a number 
of dumb-bells ranged end to end. Further maceration in caustic 
potash resolved them into a series of transverse ridges across each 
sporidium, with small globules between each pair of ridges. The 
sporidia, though long, are extremely slender, so that it is very diffi- 
cult to make out their structure. Specimens of Zorrubia Robertsit 
from New Zealand were shown for comparison. 
Microthamnion Kitzingianum exhibited—Mr. Crowe showed 
examples of that minute arborescent Alga Microthamnion Kutzingi- 
anum, somewhat widely distributed, but always scantily represented 
and fitful in appearance. It forms an elegant very tiny little bushy 
tuft of bright green colour. 
