THE HISTORY OF A DISCOVERY I4I 



cognised the organism in Laurentian rocks in Ba- 

 varia and elsewhere in Europe, and discovered a new 

 species in the Huronian of Bavaria.^ Eozoon was 

 recognised in Laurentian Hmestones in Massachu- 

 setts ^ and New York, and there has been a rapid 

 growth of new facts increasing our knowledge of 

 Foraminifera and other humble animals in the suc- 

 ceeding Eozoic and Palaeozoic rocks. Special interest 

 attaches to the discovery by Mr. Vennor, and by 

 Walcott and Matthew, to be mentioned in the sequel, 

 and tending to bridge over the interval between the 

 Laurentian fossil and those of the Lower Cambrian. 

 Another fact, whose significance is not to be over-esti- 

 mated, is the recognition both by Dr. Carpenter and 

 myself of specimens in which the canals are occupied 

 by dolomite or by calcite like that of the organism 

 itself I have made several visits to the locality at 

 Petite Nation originally discovered by Mr. Lowe, in 



* Ueber das Vorkommen von Eozoon^ 1 866. 



* By Mr. Bicknell at Newbury, and Mr. Burbank at Chelms- 

 ford. The latter gentleman has since maintained that the 

 limestones at the latter place are not true beds ; but his own 

 descriptions and figures lead to the belief that this is an 

 error of observation on his part. The Eozoon in the Chelms- 

 ford specimens and in those of Warren, New York, is in small 

 and rare fragments in serpentinous limestone. 



