26 
From i, », dP, d,Q calculate dx, dy: from ¥+da, w+ay, 
d,P, d,Q, calculate dv, dy; and so on. We thus arrive at 
A+da+..t+dc=a, wtdy+...+dy=B, 
the values of x and y which solve the required equation. This 
proof involves, though in a laborious way, the approximate de- 
termination of the value of z+ y./—1 required, by use of small 
instead of infinitely small subdivisions. 
The part of the paper which relates to neutral series is recon- 
sideration of some difficulties connected with the method of the 
former paper on the same subject; it admits of no separate 
abstract. The chief point is the double approach of 
Oy — A, + A, — A, 1 «0s 1 Gan — Qonyi 
to the limiting form 
1—-1+1—1+4... ad inf. 
May 21, 1866. 
The Prestpent (H. W. Cooxson, D.D., Master of S¢ Peter's 
College) in the Chair. 
Notes on the Cetacea which have lately been taken on the 
Welsh coast, and on some other additions to the 
Museum of Comparative Anatomy. By J. W. 
Cuark, M.A. 
Arter a short sketch of the present state of knowledge of the 
Cetacea, and a few words on the difficulty of obtaining speci- 
mens in a perfect condition, Mr Clark described some examples 
of Delphinus Tursio which had recently been obtained for the 
Anatomical Museum at Cambridge. These were from a shoal 
of sixteen which came ashore near Holyhead, of which two 
