PROCEEDINGS OF SOCIETIES, 85 
much so as to produce a rather pretty microscopic object, each 
large globule being surrounded by a series of small beads, fourteen 
to fifteen in number. The vitreous quinine did not polarize, 
whilst the crystalline did. 
Dr. John Barker exhibited a form of growing stage or stand, 
contrived by him for preservation of any object on an ordinary 
slide under observation, by placing it in connection with a reser- 
voir of water, from which the fluid is conducted to the object 
under the cover by a slip of tale. This little contrivance, which 
obyiously presents many advantages, is described and figured in 
another page of the present number of this Journal, and seems 
to supply a desideratum. 
August 16th, 1866. 
Rey. E. O’Meara referred to his having shown, at last meeting 
of the Club, some specimens of Navicula convexa gathered at 
Rostrevor, county of Down, a locality which, though frequently 
searched by him, had never previously yielded results sufficient 
to reward the labour. 
Upon further examination of this gathering, several interesting 
and uncommon Diatomaceous forms were discovered. Some of 
these Mr. O’Meara regarded, after careful search through all the 
sources of information, to be undescribed. At some future time 
he hoped to be able to furnish to the Club a list of the more re- 
markable forms found therein, but he would confine himself on 
the present occasion to exhibiting one which he proposed to name 
Pinnularia plena. 
In a paper by Dr. Greville, published in ‘ Mic. Journ.,’ January, 
1859, Mr. O’Meara had found a form figured and described under 
the name of Pinnularia semiplena, which in many features bears 
a sufficiently striking resemblance to the present form, so that the 
latter may be ultimately identified with it. Nevertheless, upon a 
careful comparison of the two forms, such differences of character 
presented themselves to notice as to justify Mr. O’Meara for the 
present in regarding them as distinct. 
The following is Dr. Greville’s description of Pinnularia semi- 
lena :— 
& Valves linear-elliptical, sub-acute ; costz radiate, distant, very 
short in the middle, and becoming gradually longer towards the 
extremities, leaving an elongate, lozenge-shaped, centrical blank 
space. Length, 0024"; breadth, about 0006"; costs, 15 in -001”, 
Pinnularia plena (O’Meara) may be thus described :—Valves 
broadly elliptical, subacute ; costz radiate, close, becoming longer 
towards the centre, leaving an elliptico-lanceolate central blank 
space. Length, ‘0024’; breadth, -0012"; cost nearly twice as 
many in same space as in P. semiplena. ; 
To complete the comparison, Mr. O’Meara observed that, in 
