Jan. 7.] special general meeting. 157 



occurs at isolated spots in a tract of 500 miles. The English E. 

 elliptica is about 400 miles away from its Hanoverian type. These 

 species were probably represented at their several epochs by isolated 

 communities in distinct lakes, lagoons, and deltas ; just as some of 

 the recent species are recognized at different localities, occasionally 

 far apart : thus E. gigas has been found in pools at Strasbourg, at 

 Toulouse, and in Tunis (the first and last upwards of 800 miles 

 apart); E. Dahdlacensis is known to live in both Abyssinia and 

 Mesopotamia (1600 miles apart) ; and E. Melitensis at Malta and in 

 Sicily (at least 50 miles apart). There are, however, very many more 

 species recorded as existing at the present period (22) than we have 

 found fossil in the deposits of any one past period, only two at 

 most being the number of known species for any one of the recognized 

 great formations. This, however, is partly due to zoological distinc- 

 tions founded on the limbs and other parts of the body in some of 

 the existing species, but not recognizable in the fossil state ; partly, 

 perhaps, to imperfect search in the strata ; and possibly, in some 

 degree, to a greater differentiation of the more modern forms, if their 

 specific distinctness is accurately determined *. 



Further search for, and strict examination of, fossil and recent 

 specimens, with careful records of the exact conditions of the strata 

 imbedding the former, and of the habitats of the latter, are necessary 

 before we can be satisfied on many of the points, referred to above, 

 in the geological history of Estheria and its Phyllopodous allies. 



On the Flora of the Devonian Period in North-Eastern 

 America. Appendix. By J. W. Dawson, LL.D., F.R.S., F.G.S. 



[Published in the February Number of the Journal, by permission of the 

 Council. See vol. xviii. p. 329.] 



January 7, 1863. 

 SPECIAL GENERAL MEETING. 



It was Resolved : — 



I. That the number of Foreign Members be in future limited 



to Forty, instead of Fifty as heretofore. 



II. That a Class of Foreign Correspondents be instituted, not 



exceeding Forty in number. 

 III. That the Foreign Members shall be elected out of the list 

 of Foreign Correspondents. 

 It was also Resolved that the Meetings of the Society shall be held 

 in the Society's Eooms at Somerset House, on and after the Anni- 

 versary Meeting next ensuing. 



* Some of the recent species are known only by their carapaces ; and, if 

 fossilized, would be with difficulty discriminated one from the other. The deter- 

 mination by the valve-characters alone is as likely to lead to an over-estimate of 

 the number of recent species, as to a too cautious consideration of the fossil 

 species. 



