THE APPEARANCE OF LIFE ON THE GLOBE 325 



After the sensational discovery of Barrande, the 

 primordial fauna has been found in nearly every 

 direction, in Sweden, England, Spain, and America ; 

 in France, it for a long time escaped the search of 

 geologists, till Bergeron had the good fortune to 

 discover it in 1888 on the Southern slopes of the 

 Montagne Noire. But already, at^that date, the 

 fauna of the Paradoxides had been despoiled of its 

 halo as being the most primitive of all. Dr. Hicks 

 had, in fact, discovered in the very lowest Cambrian 

 strata in Wales, near the small town of St. Davids, 

 the rudiments of a new fauna having certainly great 

 affinities with that of Bohemia, but distinguished 

 from it by its genera of Brachiopods, and situated, 

 without any possible doubt, still lower than the 

 layers characterized by the genus Paradoxides. The 

 fauna of the lower Cambrian was not long after 

 discovered in various regions, and was characterized 

 by a special genus of Trilobites, the Olenellus, dis- 

 tinguished from Paradoxides by its shorter cephalic 

 points and its fewer segments in the thorax. Through 

 these discoveries, the fauna of Bohemia ceased to 

 be the primordial and fell back to its former state 

 of characteristic middle Cambrian fauna. 

 ^ In the present state of our knowledge the total 

 number of fossil animals collected from the whole 

 thickness of the Cambrian soil all over the globe 

 forms a very remarkable whole, the most essential 

 characters of which we must analyse. There are first 

 simple traces, the footprints of animals in the sand 

 or the marine slime. Palaeontologists are puzzled by 

 these imprints and know not to what zoological 

 group they should be ascribed. They must often 



