DUBLIN MICROSCOPICAL CLUB. 409 
Dusrin Mrcroseorican Cius. 
March 18th, 1875. 
Observations as to the Appearance of Hexagonal Markings on Pul- 
villi of Flies’ Feet.—-Mr. Porte drew attention to the hexagonal and 
lozenge-shaped markings frequently observed on the under surface 
of the pulvilli of flies’ feet. He considered that this appearance 
had been misinterpreted, and that the markings are not corruga- 
tions of the membrane, but are really produced by the compression 
of the tubular hairs with which the under surface is clothed, like 
velvet pile. He pointed outa portion of the foot which was torn 
and which exhibited the hairs separated a little from one another 
and retaining the hexagonal shape produced by the compression. 
Diatoms from a Freshwater Deposit found in Vancouver's Isiand. 
—Rev. E. O’Meara reported on a sample from a freshwater diato- 
maceous deposit recently sent by the Club’s corresponding mem- 
ber, Dr. Moss, R.N., found on Vancouver’s Island. Mr. O’Meara 
called special attention to one form, which occurred with tolerable 
frequency, identical with that which a few meetings previously he 
had submitted to the Club, found by him in Lough Neagh, near 
Lurgan, and named by him Navicula Kittoniana. This species 
had been previously described by Mr. Kitton, who considered it 
identical with Navicula americana, Ehrenb., but Mr. O’Meara 
having had the opportunity of inspecting some specimens of the 
last-named species (kindly supplied by Mr. Kitton), he considered 
that the form in question is distinct from Wav. Bacillum, but iden- 
tical with Mav. americana ; in the former the frustule is much 
smaller, perfectly linear, and the strie extend much nearer the 
median line ; in the latter the frustule is constricted, the band of 
striz not reaching the median line. 
Zoospore Condition of Noctiluca.—Dr. Moss, R.N. (correspond- 
ing member of the Club), showed some elegant drawings of the 
zoospore condition of Noctiluca, which he had independently 
worked out, at the time unaware of Cienkowski’s Memoir, in 
Schultze’s ‘Archiv f. mikr. Anatomie,’ descriptive of their 
development. 
Rotifer citrinus, exhibited.—Dr. J. Barker exhibited a rotifer 
he considered to be Rotifer citrinus (‘ Pritch. Infus.’), the trochal 
discs less separated, the body more yellow-coloured than in R. 
vulgaris, and showing longitudinal plice. 
Cosmarium holmiense, ~, Lundell, and Cosm. anceps, Lundell, 
new to Ireland.—Mr. Archer recorded the occurrence in the same 
gathering and showed examples of Oosmarium holmiense, B, Lun- 
dell ( De Desmidiaceis,’ p. 40, t. II, f. 20), and Cosmariuwm anceps, 
Lundell (‘ De Desmidiaceis,’ p. 48, t. III, f. 4), both seemingly new 
to Britain. They were taken on Bray Head. The only previous 
examples of Cosm. holmiense he had seen were those brought 
v from the Falls of the Rhine, by Dr. Barker and Mr. Crowe; of the 
