walcott.] NEW BRUNSWICK AND CAPE BRETON. 61 



of St. John, as observed by Dr. Robb and himself. Referring to the 

 probable ages of the two groups he states that the only fossils discov- 

 ered consist of vegetable impressions found by Dr. Robb at several 

 localities, and some black scale like fragments of shells that he found 

 about the city of St. John in loose pieces of siliceous slate. At several 

 points the layers of rock in place are crowded with these remains, the 

 more entire of which presented the form and markings of a Lingula. 



Dr. J. W. Dawson described in 1862 the strata about St. John, and 

 published a section 1 that includes the shales and slates of the vicinity 

 of the city; and, in the same section, a series of beds which have since 

 proved to be of Devonian age. He states that the age of the lower 

 members was less certain. They may represent either the Middle and 

 Lower Devonian, or may be in part of Silurian age. " The only deter- 

 minable fossil, the Lingula of the St. John shales, affords no decisive 

 solution of this question." 



In proposing a classification for the pre-Devouian rocks of New Bruns- 

 wick, Mr. G. F. Matthew 2 states that Gesner's older group is to a 

 great extent younger than his upper series. He reviews the classifica- 

 tion of Dr. Dawson 3 dividing the formations into several groups; pro- 

 posing the name St. John group for Nos. 5 and 6 (in part) of Dawson's 

 section of 1862. He says that the St. John group is formed of several 

 zones of soft, black, dark gray, finely laminated shales, alternating with 

 zones of coarser gray slates, containing numerous thin beds of fine- 

 grained sandstone, the whole having a thickness of about 3,000 feet. 

 The fossils noticed were a Lingula, a Oonchifer, Annelids and Coprolites. 4 

 TheOoldbrook group, No. 6 of Dawson, in part, is given a thickness of 

 3,000 feet or more composed of greenish gray slate, bright red slaty 

 conglomerate and dark red sandy shale, with a reddish conglomerate, 

 grit aud hard, gray sandstone. The paper is accompanied by a map 

 showing the geographical distribution; also a section crossing the dis- 

 trict in the vicinity of St .John. In a foot-note mention 5 is made of 

 the discovery of numerous trilobites of two or three species, but they 

 were so excessively distorted that the genera could not be made out. 



In some observations on the geology of southern New Brunswick, 

 Prof. L. W. Bailey 6 reprinted the table of formations published by Mr. 

 Matthew in 1863. In a table on page 14 he places the St. John group 

 at the base of the Lower Silurian as an equivalent of the Potsdam or 

 Primordial of New York and the Quebec group of Canada. A full de- 

 scription of the St. John group is given, 7 and accompanying it a letter 



1 On the flora of the Dovouiau period in northeastern America. Quart. Jour. Geol. Soc. London, vol. 

 18, 1862, i>. 303. 



2 Observations on the geology of St. John County, New Brunswick. Canadian Nat., vol. 8, 1863. p. 

 243. ' 



3 Op. cit., p. 242. 



4 Op. cit., p. 244. 



* Op. cit., p. 247. 



• Observations on the geology of southern New Brunswick. Fredericton, 1865, p. 8. 

 T Op. cit., pp. 26-31. 



