178 
Observations on the Pyrocystece . 
which rarely cone in this country, were in fruit. A great feature of 
the garden was the lovely Tropceolum speciosum, which was climbing 
over the trees in the freest way, thoroughly at home. 
On Tuesday afternoon the members of the section, under the 
guidance of several local botanists, among whom was Mr. S. A. 
Stewart, curator of the Belfast Museum and author of the “Flora 
of N.E. Ireland,” visited Colin Glen, about an hour’s drive from 
the city, by kind permission of the proprietor, Mr. McCance, and 
several interesting plants were gathered. The locality is particularly 
rich and singularly beautiful. The members were entertained to 
tea by Mr. and Mrs. George Kidd, who earned the warm gratitude 
of their guests by their delightful hospitality, a gratitude which was 
suitably expressed in a little speech by the President of the Section. 
OBSERVATIONS ON THE PYROCYSTECE, 
By V. H. Blackman, M.A. 
Assistant, Department of Botany, British Museum. 
With Platk IV. 
HE family of the Pyrocystece comprises but a single genus. 
Pyrocystis, a name aptly given, during the voyage of the 
“ Challenger,” to two unicellular free floating organisms 6n 
account of their strong luminous power. One of the organisms 
being similar in form and luminosity to the interesting member 
of the Cystoflagellata, Noctiluca, received the name of P. pseudo- 
noctiluca, while the other, owing to its shape, was called 
P. fusiformis. They were first figured and briefly mentioned by 
John Murray (6) 1 in 1876 , but the names appear under the authority 
of Wyville Thomson. These two forms are often found in abun¬ 
dance in the surface waters of most tropical and sub-tropical 
’In this paper the names appear as P. pseudonoctiluca Wy. T and 
P. fusiformis Wy. T.,but curiously enough in the “Challenger” 
narrative ( 7 ) they appear asP. noctiluca Murray and P. fusiformis 
Murray. In this form and under this authority tliay have 
passed into general literature, but it is, of course, the first 
published names that must stand. 
