DUBLIN MICROSCOPICAL CLUB, 417 



" Irish elk.'' It contained nearly all the species of Epithemia in- 

 cidental to the freshwater and in the greatest abundance. More 

 s|)aringly were found some common species of Navicula, such as 

 iV". major, N- nobilis, JV. viridis, &c. ; Campylodiscus costatiis also 

 occurred. But the most remarkable form was one which Mr. O'Meara 

 considered to belong in all probability to the genus Colletonema. 

 The tubes, with the frustules included, were numerous, greatly 

 broken, and ever appearing to be simple. The included frustules 

 were very small, decidedly navicular, with very faint striae. Mr. 

 O'Meara proposed to designate this form as Oolletonema Hiber- 

 nicum. 



Conjugated state of undescribed Cosmarium shown at preceding 

 meeting of the Club. — Mr. Crowe showed the conjugated state of 

 the Cosmarium brought forward by him at the last meeting of the 

 Club, it having entered into that state very copiously in the house. 

 The zygospore is large, thick-walled, and smooth, thus like that of 

 Cosmarium Broomei, to which species, however, this shows no 

 further resemblance. It was very interesting to meet with the 

 zygospore so promptly in the discovery of the form itself, of which 

 more on a future occasion. 



Friiit of Anthoceros punctatus and preparation of the frond, ex- 

 hibited. — Mr. Mackintosh brought forward a longitudinal section 

 of the young fruit of Anthoceros punctatus, showing the columella 

 running up the middle and the spores arranged on each side. He 

 also showed a preparation of the growing edge of the frond, each 

 of the cells of which had the characteristic single, large, irregularly 

 stellate chlorophyll-body. The specimens were given to him by 

 Professor E. P. Wright ; they had appeared spontaneously in some 

 peat in the orchid-house of the College Botanic Gardens, which had 

 been brought from a bog near the " Sugar- Loaf " Mountain. 



Cosmai'ium amiulaturn, Niig., and three neighbouring new forms, 

 exhibited. — Mr. Archer exhibited three cylindrical forms of Cos- 

 marium, one of which he thought to be identical with Cosm. annu- 

 lafum, Ntigeli, and a drawing of a fourth ; three of the four now 

 drawn attention to he believed to be new. Two were truncate (one 

 of these being the Cosmarium annulatum), and two were rounded 

 at the extremities. Mr. Archer would hereafter, he hoped, be able 

 to prepare descriptions of these forms in full, and merely brought 

 them forward now as a little series of kindred forms to show how 

 closely such species could resemble and still be evidently mutually 

 distinct. 



Structure of leaves of Abies bifida and A. firma. — Dr. McNab 

 exhibited transverse sections of the leaves of Abies bifida and Afirma. 

 A. bifida is distinguished by having the resin-canals close to the 

 epidermis of the under side of the leaf, and by having peculiar elon- 

 gated thickened liber-like cells in the parenchyma of the mesophyll. 

 A. firma, on the other hand, has the resin-canals in the parenchyma 

 of the mesophyll, and has no thickened liber-like cells. The two 

 forms are very distinct although given as synonymous by Parlatore. 



