Raymond: Thk ('hazy For.maiion and its Fauna. r)()5 



This zone has been found only at Chazy, but it is there very 

 strongly marked. It ocxurs about 75 feet below the ba.se of Division 2. 



The characteristic fossils are : Lophospira subabhreviaia and Raphi- 

 stoma sfai/iinfion, both of which are very abundant. Of lesser impor- 

 tance are the rare Schizambon ? dupliciintiratus, Heliomera sol and 

 Clionycliia marginalis. 



Division 2 : The Macliirites inagnus Division. 



The strata of this, the middle division, are usually heavy-bedded, 

 dark-blue and gray, fairly ])ure limestones, with an occasional layer 

 of gray, sparkling dolomite or of light, coarse-grained limestone. 

 The layers near the middle weather into nodular masses, and fossils 

 are usually poorly preserved and difficult to extract. The thickness 

 varies from 200 feet at Chazy to 400 at Valcour Island and decreases 

 toward the south. 



The characteristic fossils are : Maclurites niagnns, Rafinesquina 

 clianip/ainensis, P/oisioniys plafys, PlcFsioniys strophonienoides, Strepho- 

 cJietus, Eospon^^ia varians, Eotoniaria obsoletum, Eccylioptcriis freder- 

 iciis, Batliyurelliis minor, Cybele prima and Leperditia limatula. 



The following fossils have so far been found only in this division, 

 but most of them have been found at only one locality : Camaroia'c/iia 

 pristina, Ctenodonta diibia/ormis, Clidophorus obscurus, Wliiteavsia ? 

 expansa, Endodesma iranccps, Uliiteavsia ? iindatiini, Scenclla robiista, 

 Rapliistomina undiilatiini, Helicotoma vagrans, Bucania bidorsata /, 

 Eccylioptcriis kalmi, Eccyliopterus proclivis, Trochonema dispar, Si/bn- 

 lites prolongata, Trochonema hiidsoni, Holopea scrutator, Eoharpes otta- 

 waensis, Asaphus marginalis, Isotelus angusticaudiim, Isoteliis ? bearsi, 

 Illcenus ptinctaius, Cerauriis pompiliiis, Ceraurus hiidsoni and Pseiido- 

 sphcerexochits approxiniits. 



This middle division is marked by the great number of species of 

 pelecypods, gastropods, and trilobites, and is, in that respect, sharply 

 contrasted with the lower division. Of the 23 pelecypods, 13 are 

 represented here. Of 40 gastropods this division contains 27, and of 

 the 38 trilobites, 27. Species of Stroma tocerinm and Strephochetiis 

 are common in the rocks of this division, but are also abundant in the 

 lower zone of the next division. 



Zone 2a. The Malocystites niiirchisoni zone. 



So far only one subfaunule has been detected in ihis division and 

 that is at the very base. It is best developed at Valcour, but occurs 



