eh 
Cambrian Rocks in Acadia. 25 
(upper) and the Caerfai (lower). The upper group has a 
thickness of 1800 feet, and in a former publication I have 
shown that its fauna is essentially equivalent to that of 
Band ¢ of Division 1 of the St. John group; but from the 
thickness of the Solva group, it seems probable that it con- 
tains also the equivalent of the Band b and perhaps of Band 
a. This being the case, we may infer that the Caerfai 
group, which has a thickness of about 1600 feet, corres- 
ponds to the lower series of the Cambrian system in Acadia. 
But the Caerfai group in Wales is not known to be uncon- 
formable to the rest of the Cambrian system, and in this 
appears to differ from the beds in Canada and Newfound- 
land, which we suppose to be of corresponding age. 
The writer is well aware that correspondence in the bulk 
or volume of measures in different countries, supposed to 
be coetaneous, is of uncertain value as a measure of 
time, but when, as in this case, it is checked at the 
upper limits by a well established faunal horizon, and 
at the base by a decided physical break, there being nothing 
in the constitution of the measures, or in the aspect of the 
known fauna, to suggest diversity of age, we are fairly justi- 
fied in considering the measures contemporaneous. 
CANADA. NEWFOUNDLAND.| G. BriTarn. Norway. SWEDEN. 
Limestone of ' 
= [Pana d. Chapel Arm in MenevianGr.| Etage 1 d. Upper eas 
= Trinity Bay. : ; 
4 Shales of M 
SP noo, 2 nel i veda ete gee Part of Upper 
58 Hote ay WH z Solvagroup) |Sparagmite| poop, Paras 
~~ 1 = 
oz parte | [formation =Ht-|aoxides Beds. 
a2 Do. b 9 | age Lb & ec. 
3a 
a Part of Upper | miante , 
‘ Solva group } |Sparagmite Fucoidal & 
n Do. a.. ? ; 2 ear Jophyton 
part ? formation = Ht- | San stone. 
age la. : 
Lower series {| Lower series! } Lower di- 
of Cambrian ||members a to e : vision of 
System in4 of the Lower Si-| ¢ Caerfai Gr. the Sparag- ? 
Acadia. Jurian (i.¢., Cam- mite ae | 
Pann) System. ation. 
