42 PROCEEDmCfS OF THE GEOLOGICAL SOCLETY. [DeC. 6, 



Trilobites, 10 genera and 30 species. 



Bivalved and other Crustaceans, 3 genera and 4 species. 



Brachiopods, 4 genera and 6 species. 



Pteropods, 3 genera and 6 species. 



Sponges, 1 genus and 4 species. 



Cystideans, 1 genus and 1 species. 

 By adding to these the Annelids, which are plentiful also in these 

 rocks, we get seven great groups represented in this fauna, the 

 earliest known at present in this country. By referring to the 

 Tables published in M. Barrande's excellent new work on Trilobites, 

 it will be seen that this country also has produced a greater variety, 

 or, rather, representatives of a greater number of groups from these 

 early rocks, than any other country. The species described included 

 Agnostux, 5 species ; Arionellus, 1 species ; Er'mnys, 1 species ; IIo- 

 Jocejjlialina, 1 species ; Conocoryphe, 2 species ; Anopolenus, 2 

 species ; Cyrtoilieca, 1 species ; Stenotheca, 1 species ; Theca, 2 

 species ; Protocystites, 1 species, &c. The author also entered into 

 a consideration of the range of the genera and species in these 

 early rocks, and showed that, with the exception of the Brachiopods, 

 Sponges, and the smaller Crustacea, the range was very limited. 



A description of the various beds forming the Cambrian rocks of 

 St. David's was also given, and proofs adduced to show that fre- 

 quent oscillations of the sea-bottom took place at this early period, 

 and that the barrenness of some portions of the strata and the 

 richness of other parts were mainly attributable to these frequent 

 changes. 



Discussion. 



Mr. GwYN Jeiteeys suggested that the term Polyzoa might be 

 adopted in preference to that of Bryozoa, as being the more ancient 

 terra, and that the name Proserpina should not be applied to the 

 new genus of Trilobites, as it had already been appropriated to a 

 tropical form of land-shell. 



Mr. Hicks thanked Mr. Jeffreys for his suggestions, which he was 

 inclined to adopt. 



December 20, 1871. 



Frederick H. Bowman, Esq., F.R.A.S., F.C.S., of Halifax, York- 

 shire, and Thomas Charles Sorby, Esq., F.R.I.B.A., of 27 Bruns- 

 wick Square, W.C, were elected Fellows of the Society. 



The following communications were read : — 



1. A letter from G. Milner Stephen, Esq., F.G.S., to the late Sir 

 EoDERiCK Mtjrchison, dalcd Sydney, 5 October, 1871, from which the 

 following is an extract :— 



" As I regard yourself as the prophet of gold-discovery in Aus- 

 tralia &c., I cannot refuse myself the pleasure of asking you to be- 

 come the medium of my communicating to the Geological Society of 

 London two very interesting discoveries recently made in this hemi- 

 sphere. 



