ON THE FOSSIL PHTLLOPODA OF IHE PALEOZOIC ROCKS. 181 



D. DlSCINOCARID^. 



I. Spathiocaris, Clarke, 1882. In the Portage formation. 

 1. 8p. Emersoni, Clarke, p. 199, pi. 35, figs. 12-18. 



II. DiPTEROCARis, Clarke, 1882. In the Portage and Chemung 

 formations. 



1. D. pennce-DaidaM, Clarke, p. 200, pi. 35, fig. 24. 



2. D. Procne, Clarke, p. 201, pi. 35, figs. 25-27. 



3. D. pes-cervce, Clarke, p. 202, pi. 35, figs. 20, 21. 



II. Phtllopoda. 

 A. Limnadud^;. 



I. Estheria, Riippel, 1857. In the Hamilton formation. 

 1. E. pulex, Clarke, p. 206, pi. 35, figs. 10, 11. 



II. ScHizoDiscus, n.g. (J. M. C), p. 203. In the Hamilton formation. 

 1. S. capsa, n. sp., p. 207, pi. 35, figs. 1-9. 



■Second Report of the Committee, consisting of Mr. S. Bourne, 

 Professor F. Y. Edgeworth {Secretary), Professor H. S. Fox- 

 well, Mr. Egbert Gtiffen, Professor Alfred Marshall, Mr. J. 

 B. Martin, Professor J. S. Nicholson, Mr. K. H. Inglis Pal- 

 grave, and Professor H. Sidgwick, appointed for the purpose 

 of investigating the best method of ascertaining and m.easuring 

 Variations in the Value of the Monetary Standard. {Drawn 

 up by Mr. Giffen.) 



In their reports last year the Committee discussed fully the theoretical 

 aspects of the problem of measuring variations in the value of the 

 monetary standard. It was abundantly clear, from this discussion, they 

 think, that even if statistical data were more complete than they are 

 the question is a most complicated and difficult one : how to measure 

 variations in the value of the monetary standard would in no case be a 

 simple matter. They desire now to report on one or two of the 

 more definite issues involved as connected with problems of immediate 

 practical interest, of which it may be possible for the public to attempt 

 an approximately correct practical solution. 



The main practical uses for which the measurement of variations in a 

 monetary standard has been desired appear to be the following : — - 



1. The fixation of rents or other deferred payments extending over 

 long periods of time, for which it has been desired to obtain a currency 

 of a more stable sort than money is supposed to be. This has been a 

 pi-actical question of great importance from the days of Fleetwood's 

 ' Chronicon Preciosum,' which begins, as is well known, with a remark- 

 able case of conscience — whether a man in order to receive a bursary or 

 scholarship, for which a declaration that his private income does not 

 exceed, say, five pounds a year, is required, is justified, the value of 

 money having fallen proportionately, in making the declaration upon an 

 income not exceeding thirty pounds a year. In recent times there is at 

 least one instance of a difierent standard from metal being deliberately 



