Raymond: '1'hk Ciia/v I^'ormaiion and its Kaixa. '^21 



divisions there are definite zones, marked l^y their own characteristic 

 fossils. These divisions are : 



1. IV/e Hcbertella exfoliata dii'ision. Thickness 300 feet. .1,.,. of 

 the section. Characteristic fossils : Zv^i^osfi/ra iui//iros/r/s, Jh^lbo- 

 porites aiiicricainis, and Hrhrriclla exfoliata. In si)iteof the fact that 

 this division has a consideral)le fauna, it is separated from the divisions 

 above chiefly by the absence of certain of the species of the higher 

 divisions, and it has few very characteristic species of its own. At 

 the base is a zone characterized by the abundance of Ortliis aciitiflicaia. 



2. Tlic Afae/i/rifes iiiai^iiits dri'is/oii. 'i'hickness 400 feet. V^-,., of 

 the section. Characteristic fossils : .}far/i//-i/es iiiai^/ins, J\ajiiies(/i//iia 

 c/ianip/aiiie/isis, Phesiontys p/a/vs, Cam ere/la 7'aria/is, Leperditia liiua- 

 fii/a and StrepJioebtetiis brainerdi. A few of these species are found 

 outside of this division, but by a Afae/un'/es /j/ai^;///s fauna is meant the 

 association of an abundance of these forms. This division is further 

 marked by the great number of gastropods, as, out of sixteen forms 

 known at Valcour Island, not less than twelve are restricted to this 

 division. Of trilobites, Eoharpes and Poiicliodoi/ias appear here, and 

 SpJicrrexoelii/s is rarely found above or below. 



3. T/ic Caiiiarofa'cliia plena division. Thickness 175 feet. A.,;,, 

 to toj) of the formation. Characteristic fossils: CamaroiiVcJiia plena , 

 Caniarota'chia major, Orthis ij^nienla and Afodiolopsis fabaforniis. 



Certain of the species in the Valcour Island sections range all 

 through the three divisions, as is shown in the accompanying table 

 (See p. 528). 



Slations on Idleonr Island. 



Collections have also been made at various localities on \'alcour 

 Island which are not included in any of the foregoing sections, and 

 lists from these localities will be given under the heading of stations. 

 These stations are indicated on the index map which accompanies this 

 article. (Plate XXV.) 



Station ^ ^^q. This station is on the rocks on the west side of the 

 rocky point which separates Christmas Hay from Light House IJay. 

 The rock exposed is a fairly coarse, dark-gray limestone, and con- 

 tains Afaclurifes niay;niis in great abundance. The species collected 

 are as follows : 



Monotrypella sp. c, Raphistonia stamineuni r, 



Rlixnidietxa fenestra! a c, Maelurites mai::;niis a, 



