110 NATURAL HISTORY SOCIETY 0¥ DUBLIN. 



It is worthy of notice that in some aspects the costae appear as if 

 they were slightly notched by longitudinal lines, which, though they 

 produce a furrow, do not sink so deeply as to give a moniliform cha- 

 racter to the sculpture of the valve. 



Pinnularia constricta. — N. sp., O'M., Fig. 8. Valve elliptical ; 

 length, -0044; breadth, -0014; central nodule depressed ; costse distant, 

 nearly reaching the median line, except at the central nodule ; in front 

 view constricted, linear. 



Pinnularia forficula. — N". sp., O'M., Fig. 9. Yalve broadly ellip- 

 tical ; length, -0021 ; breadth, -0014; in the middle is a blank space, 

 curved, constricted at the central nodule, and towards the apices from 

 each side converging to a point. The striae are distinctly costate, and 

 longer at the middle than towards the apex. 



This form closely resembles in its outline Navicula Smithii, var. 

 suborbicularis, described by Gregory in his paper on the Diatomaceae of 

 the Clyde, but is distinguished from it by its costate striae. 



Surirella pulcherrima. — "N. sp., O'M., Fig. 10. Length, -0046; 

 breadth, -0037 ; broadly elliptical, ends symmetrical, and nearly lan- 

 ceolate ; the border narrow, the central area wide, elliptico-lanceolate, 

 and striate at the margin ; canaliculi about 1 5 on either side, at first nar- 

 row, then expanding towards the outer margin, the narrow part short 

 and robust ; alae conspicuous. 



Surirella gracillima. — ~N. sp., O'M., Fig. 11. Length, -0055 ; breadth, 

 •0037 ; ends symmetrical, and broadly rounded ; canaliculi about 24 on 

 either side, slightly radiate, narrow at first, and expanded towards the 

 outer margin ; the narrow portion long, the expanded part first rounded, 

 and at a short distance from the junction slightly constricted, and gra- 

 dually enlarging till it approaches the margin, when it terminates in a 

 rounded end, separated from the next one by a very small space; outer 

 margin finely striate, as is also the margin of the central area, which is 

 elliptical ; alae not conspicuous. 



The following paper was then read: — 



On a JSTew Station of Hymenophyllum Wilsoni and H. Tunbeidgense. 

 By F. J. Foot, M. A., F. E. G. S. I. 



Considering it to be highly interesting and important as regards distri- 

 bution to note the occurrence of such local plants as the species of Hy- 

 menophyllum, I beg to bring before the notice of the Society this even- 

 ing a station of both species of that genus, which I believe to be hitherto 

 unrecorded. It is ou Slieve Anierin Mountain, in the county of Lei- 

 trim, which lies at the side of Lough Allen. Slieve Anierin (the 

 iron mountain) is 1922 feet above the level of the sea, and 1720 

 feet above the lough ; it is composed of the black coal-measure shales, 

 surmounted by beds of white and light yellowish brown, hard quartz- 

 ose grits, some of which are conglomeritic, and often pass into 



