Palcoiitological Speculations. — Gratcap. 215 
alas ojiiistns (Geolog}^ of Wisconsin, Vol. IV, p. 183) where 
he writes, "there seems to be an ahiiost endless variety of 
this group of trilobites preserved in the rocks of this period,, 
differing principally in the combination of features as shown 
in the cephalic shield. The numerous species are readily 
recognized, however, by the form of the fixed cheeks and 
glabellas, even where no other part of the animal can be de- 
termined ; and though it may appear incredible, entirely new 
forms are presented among the specimens obtained from each 
individual locality." 
Dawson, Hartt and Matthews have similarly indicated 
the abundance of trilobitic remains in the Acadian fauna at 
Ratcliffe's Mill-stream, St. Johns, and elsewhere in New 
Brunswick, "where some of the layers are perfectly loaded 
with fragments of trilobites." 
Matthew also says in his paper on die "Fauna of the St. 
John group" (Transactions Royal Soc. of Can., 1891, p. 55) 
"in the black slates of the Bretonian Division there are locally 
immense numbers of minute trilobites which appear to rep- 
resent in the economy of nature the swarms of Agnosti that 
are found in the fine shales of the Acadian division and were 
there buried in the fine mud that entombed the Paradox- 
ides." 
The language of Barrande is well known (Systeme Silur- 
ien de la Boheme. \"ol. I, Suppl., p. 397) "sous le rapport de 
la frequence des individus, on sait que dans toutes les con- 
trees ou la faune primordiale est connue, les restes des tril- 
obites, paraissent innombrables tandisque les traces des 
autres fossiles sont rares. Ainsi, en Boheme on peut estimer 
la frequence des trilobites, comme au moins centuple de celle 
de toutes les autres formes fossiles. Cette estimation est 
probablement beaucoup audessous de la verite. D'apres les 
descriptions des savans, il en est a peu pres de meme dans 
toutes les autres contrees, sur les deux continens." 
The researches of Walcott and AIM. Brogger & Schmidt 
have now definitely aided paleontology^ in establishing three 
zones or faunal expressions to the Cambrian day, the Olen- 
ellus (annelidan), Paradoxides, and Olenus. The vertical 
separation, in sediments, of these beds is represented in 
•Nous n'y trouvous cependant ancum type de trilobite que Ton puisse con- 
siderer comme appartenant a une famille distincte de ceux des couches a Para- 
doxides. 
