PROCEEDINGS OF THE SOCIETY. 
247 
sequatorialis. Staff-surgeon Gunson Thorpe subsequently found the 
same form in the Botanic Gardens at Brisbane. When on the China 
Station he went up the Yang-tze-kiang river a distance of about 200 miles, 
and there found another species of the same genus which had the wreath, 
not round the middle as before, but round the upper portion about where 
the Tropic of Cancer would be marked upon the globe, and on this 
account he gave it the specific name of solstitialis. It was again found 
in America in 1896 — and also in 1898 — by Dr. Kofoidand Mr. Jennings. 
Some specimens of the last-named find had been sent to Mr. Rousselet, 
and the specimen placed under the Microscope in the room was, he 
believed, the first of the genus ever seen in England. In addition to 
the specimen exhibited, Mr. Rousselet further illustrated his remarks by 
a drawing on the board, in which he showed the nervous system, and also 
the position of the cloaca, which Mr. Gunson Thorpe had considered to 
be on the ventral side, although in this he was possibly mistaken. (See 
p. 162.) 
The thanks of the Society were unanimously voted to Mr. Rousselet 
for his interesting exhibit and description. 
Mr. Lewis Wright then gave an exhibition of Microscope slides by 
means of his improved projection Microscope. He said that fourteen-and- 
a-half years ago he came to the Society with Mr. Newton, and showed 
what could be done at that time with the projection Microscope, 
and he hoped on the present occasion to show them what progress had 
been made meanwhile. He regretted to find that he should be unable 
to show them the best that could be done, because he was prevented 
from using the electric light by reason of the available current being 
insufficient for the purpose ; he must therefore fall back upon the old 
lime light ; and as this was what he had used on the former occasion, 
perhaps the comparison could be even better made as to real improve- 
ments in lantern microscopy, apart from merely better illumination. 
These improvements were several. In condensers, it had been found 
very much better to use a four-lens condenser, by which it was possible to 
practically abolish the spherical aberration. He had also learned from 
the President of the Society the necessity for regulating the cone accord- 
ing to the aperture of the objective. Then the tine adjustment had also 
been greatly improved and rendered steadier by the adoption of strength- 
ening bars and a differential screw. There had of course been also 
great improvements in objectives since he exhibited before, and these 
were the more available because all the best lantern work was now done 
with eye-pieces, which had, however, for screen demonstration, to be 
much larger in field than the well-known projection eye-pieces of Zeiss. 
Another important improvement had also been made in the screen, 
which was covered with a thin coating of silver, this rendering it more 
highly reflective and greatly increasing the brilliancy of the pictures. 
A plain silvered surface would not answer, as the image could then only 
be seen by persons in front of the screen, but he had found that by 
having the surface minutely ribbed or striated in a vertical direction, the 
light was so reflected from it that persons sitting at the sides could see 
quite well. Mr. Wright then proceeded to show a large number of 
