Revieivs — Prof. C. Lapworth's Canadian GraptoUtes. 369 



life-groups, as they occur in each stratum, is the only method open 

 to the geologist who aspires to lay the foundations for an enduring 

 scheme of classification. 



The collection of Graptolites treated of in this Eeport was for- 

 warded to Prof. Lapworth by Dr. A. E. 0. Selwyn, F.R.S., Director 

 of the Geological Survey of Canada, the material having been accu- 

 mulated by various members of the Stafi" of the Survey at different 

 periods dating from 1876. 



The Graptolites were found to belong to several distinct zones, 

 each corresponding with a distinct zone in Great Britain and Western 

 Europe, and ranging from the British Tremadoc Slates to the middle 

 of the Bala or Caradoc Formation of Wales and the West of 

 England. 



The Graptolite zones are here briefly described : — 



Zone I. — Cape Bosier Zone: Zone of Dictyonema sociale and 

 Bryograptiis. 



This is the oldest represented, and it occurs at the Barrasois 

 Eiver, Cape Breton Island, and at Cape Eosier, Gaspe ; as well as 

 at other points along the south shore of the St. Lawrence. In 

 Europe it occurs in the Tremadoc of Wales and the Tremadoc and 

 Ceratopyge Beds of Norway (Brogger) and Sweden (Tullberg). It is 

 of Upper Cambrian age. 



Zone II. — Ste Anne Zone: Zone of Phyllograptus Anna; Grap- 

 tolites from Eocks three miles above Ste Anne des Monts, 



This zone contains the following four species of Graptolites; 

 Tetragraptus bryonoides, Hall ; T. fruticosiis, Hall ; Phyllograptus 

 Anna, Hall; Pidymograptus extensus, Hall. "These are all well- 

 known Point Levis species, according to the classical monograph of 

 Prof. Hall,^ and they also occur together upon the corresponding 

 Arenig-Skiddaw horizon in Europe, in the Shelve Arenigs, in the 

 Skiddaw Slates, and in the Phyllograptus beds of Norway and 

 Sweden." 



The author remarks upon the absence of this Ste Anne Phyllo- 

 graptus zone in the collection among the fossils eastward of the 

 Ste Anne Eiver, though the lithological characters of these strata 

 point to the persistence of such a zone for great distances. 



Zone III. — Griffin Point or Marsouin River Zone : Zone of Coeno- 

 graptus gracilis. 



This supplies the largest number of species in the collection. 



The most characteristic forms are Pidymograptus Sagittarius (Hall, 

 non Hisioger) ; C<enograptus gracilis. Hall ; Picellograptus sextans, 

 Hall ; Lasiograptus mucronatus, Hall ; Climacograptus antiquus. Lap- 

 worth ; Diplograptus Whitfieldi, Hall, " and the presence of a single 

 one of these species is sufficient to settle the age of the rock in Great 

 Britain, and in all likelihood in America." But there are associated 

 vidth them a few species which enjoy a more extended range in time, 

 such as the well-known Hudson Eiver form, Bier ana graptus ramosus, 

 Hall. 



1 Canadian Organic Eemains, Decade ii. 1865, " Graptolites of the Quebec 

 Group." 



DECADB III. VOL. IV. J\0. YIII. 24 



