of Edinhurgh, Sessioii 1862-63. 
47 
Sul)-class 2d. — Animals free, locomotive. — Pelagic Tunicata. 
II. Branchial membrane sac-like, with transverse slits in single 
longitudinal series, strengthened by longitudinal non-ciliated rods, 
apertures terminal or sub-terminal. 
III. Kespiring by an upper and a lower gill-band, connected 
with each other laterally, and with the walls of the atrium ; having 
branchial slits, but no supporting longitudinal rods ; apertures 
terminal. 
IV. Eespiring by a central and inferior gill-band, with free 
borders and transverse ciliated stripes, but without slits or rods ; 
apertures terminal or sub-terminal. 
V. Pharynx ciliated below, without a distinct gill-band ; bran- 
chial slits reduced to two ciliated openings on the sides of the 
rectum. 
The authoj concludes his paper with remarks on several of the 
genera, in reference to the position assigned to them in his classi- 
fication, and with some details as to the anatomy of Orthocala — - 
the Saif a 'pinnata of authors. 
2, On the great Kefractor at Elchies, and its powers in 
Sidereal Observation. By Professor C. Piazzi Smyth, 
Astronomer-Eoyal for Scotland. 
The telescope here referred to is the largest and best ever erected 
in Scotland, for exact sidereal observation ; and the author having 
paid a visit last September to its liberal and hospitable owner, J. 
W. G-rant, Esq., of Elchies, Morayshire, had an opportunity of 
trying its powers oji double stars, and describes the results of the 
trial in his paper. 
Out of a list of twenty-nine double stars, there were six cases 
where one or more new small stars were discovered ; and the ob- 
servations of position and distance on the older members of each 
group were so trustworthy, as to add valuable information towards 
elucidating both the proper motion of some optical double stars, 
and the orbital motion of several binary ones. In addition to 
which, several unexpected results were arrived at with reference to 
cosmical changes in the magnitudes and colours of certain stars. 
