NO. I FORMATIONS OF BEAVERFOOT-BRISCQ-STANFORD RANGE 37 



The four faunal zones of the Mons are characterized, as far 

 as known, by some one genus that attains its greatest development 

 in each zone (see figs. 6, 7, 8 and 9, p. 38). 



The upper zone has Ozarkispira leo (fig. 6, p. 38) and a con- 

 siderable group of other gasteropods associated with it. 



The Hungaia zone (fig. 7, p. 38) is marked by a great development 

 of that genus. 



The Syntphysurina zone (fig. 8, p. 38) has the greatest vertical 

 range, as representatives of it occur in the basal beds of the Hungaia 

 zone and for about 1,400 feet (426.7 m.) beneath. 



The Briscoia zone (fig. 9, p. 38) ranges through the lower part 

 of the Mons, but is usually confined to a limited thickness of beds. 



In considering these zones it must be borne in mind that they are 

 based on limited study and collecting, and that future discovery may 

 extend and combine them or more clearly limit their range. 



OZARKISPIRA LEO Walcott n. sp. 

 Fig. 6. ( X 2.) Side view and view of spire from above 

 This is the type species of the genus. 



Locality. ^^4t, Ozarkian, Mons formation. Fossil Mountain, 8.7 

 miles (13.9 km.) northeast of Lake Louise Station on the Canadian 

 Pacific Railway, Alberta. Canada. 



HUNGAIA BILLINGSI Walcott n. sp. 



Fig. 7. (Nat. size.) Diagrammatic outline of the cephalon, thoracic segments, 



and pygidium 



This is the type species of the genus. 



Locality. — 6iq, Ozarkian, Chushina formation. Billings Butte 

 (Extinguisher), Robson Peak District, British Columbia, Canada. 



SYMPHYSURINA WOOSTERI Ulrich n. sp. 



Fig. 8. ( X -2.) Diagrammatic outh'ne of cephalon and pygidium 

 This is the type species of the genus. 



Locality. — 193, Ozarkian, Oneota Dolomite. Trempealeau, Wis- 

 consin. 



BRISCOIA SINCLAIRENSIS Walcott n. sp. 

 Fig. 9. (Nat. size.) Diagrammatic outline of a cephalon, thoracic segment, 



and pygidium 



This is the type species of the genus. Fragments of this species 

 occur that indicate individuals more than twice as large as the 

 above figures. 



Locality. — i6t', Ozarkian, Mons formation. North side of Sin- 

 clair Canyon above Radium Hot Springs. South end of Brisco 

 Range, British Columbia, Canada. 



