166 Proceedings of the Royal Society 
chambers of construction and the overlappings of the grand 
gallery. 
Diagram No. 5. — Independent method of constructing the G-reat 
Pyramid in its external angles from a unit angle oblong. 
Diagram No. 6. — John Taylor’s theory of the reference the 
G-reat Pyramid bears to the circle, with Professor C. Piazzi Smyth’s 
amplification of the same, and further amplification by the author. 
3. On the Structure of Tubifex. By W. C. MTntosh, M.D. 
The paper consisted of a detailed account of the external form ; 
the arrangement of the body-cavity and its walls; the perivisceral 
space and corpuscles ; the digestive, circulatory, and generative 
systems. 
It was specially mentioned, in regard to the perivisceral cor- 
puscles, that the author was not at all inclined to think that they 
originated from the glandular fatty coating of the digestive tract 
and the dorsal blood-vessel. The corpuscles seem rather to he the 
product of the perivisceral cavity itself and its special (free) con- 
tents. This view requires no stretch of ordinary physiological 
principles, and is quite in keeping with what is found in other 
groups. In the Nemerteans, for instance, a complex corpusculated 
fluid is produced within a closed chamber with smooth walls. 
The following Gentlemen were elected Fellows of the 
Society 
James Sime, Esq. 
Thomas Harvey, LL.D. 
John Young Buchanan, M.A. 
John Hunter, M.A., Belfast. 
The Bight Hon. The Lord Justice-Clerk. 
The Hon. Lord Gifford. 
