ART. 21 ORDOVICIAN TKILOBITES ULRICH 49 



with the graptolites or by themselves in tlie basal quarter of the 

 Athens shale. This is true whether the Athens consists entirely of 

 the shale f acies or begins with or consists entirely of the limy facies. 

 The case, however, is very different when we try to fix the position 

 of the Telephus occurrences in southeastern Canada in the sequence 

 of Chazyan deposits in the southern Appalachian troughs. The 

 species in the former region are not precisely the same as their con- 

 geners in the south. None of the latter could be unquestionably 

 identified with T. mysticensiSy which is the name proposed in the 

 paleontological part of this paper for the species found in the 

 limestone conglomerate near Mystic in the southwestern corner of 

 Quebec. 



Ahsence of Telephus faunas in Chawi'plain Y alley. — Except the 

 Valcour limestone, which is the top limestone of the Chazy in the 

 Champlain and St. Lawrence Valleys and probably falls into some 

 undetermined part of the stratigraphic span covered by the Blount 

 group of east Tennessee, no deposits of Blount age occur in place 

 between Virginia and the Mingan Islands in the Gulf of St. Law- 

 rence. Disregarding the Valcour — mainly because its fauna is quite 

 dissimilar to all but the highest (Ottosee) fauna of the Blount — 

 we may therefore assume that the Appalachian troughs north of 

 Virginia and south of Canada were emerged during the deposition 

 of the 6,000 feet or more of beds comprised in the Holston, Whites- 

 burg, Athens, and Tellico formations of east Tennessee and in the 

 second, third, and fourth of which remains of Telephus are found. 

 If we were to assume that the Tellico occurrences of Telephus 

 marked the termination of the existence of the genus we might 

 then conclude that the occurrences of the genus in Canada and 

 Europe are older than the top of the Tellico. But we would have 

 to assume or prove also that the foreign occurrences are not older 

 than the Whitesburg limestone before we could say that any of the 

 concerned Chazyan formations on the two sides of the Atlantic are 

 contemporaneous. 



Discussion of age relations of faunojs in Scotland to Appalachian 

 faunas. — On the basis of direct faunal comparisons it seemed at first 

 one might find sufficient evidence to indicate that the Balclatchie 

 group in the Girvan District in Scotland — from which Reed described 

 Telephus salteri — comes nearer to an agreement with our Whitesburg 

 limestone than with any other of the Appalachian formations. Cor- 

 roboration of this suggested correlation appeared also in the fact 

 previously pointed out by Raymond ^° that species of Dionide occur 



=" Raymond, P. E., Some trilobites of the Lower Middle Ordovician of eastern North 

 America : Harvard Coll. Mus. Comp. Zoiil. Bull., vol. 67, No. 1, p. 179, 1925. 



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