PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 27 
Lowville formation.—The lowest Ordovician rocks of the region are ex- 
posed on the west side of Cloche Peninsula and consist of at least 60 feet of 
reddish clay shale that produced a few fossils. The only brachiopod recorded is 
Lingulella clochensis (Foerste). 
Swift Current formation.—This consists of a possible 50 feet of section ac- 
cording to Foerste’s estimate. The lower beds are reddish limestone or dolomite 
with fragmental material at the base in which are mixed a number of Ordovician 
species. The higher beds are of fine-grained, white, “birdseye’’ limestone poor in 
fossils. Except for the basal beds, few fossils occur except at the base of the 
white “birdseye” limestone where the same fauna as that at the base is found. 
Foerste lists the following brachiopods: 
Pionodema sp. 
Rhynchotrema ainsliet (N. H. Winchell) = Rostricellula rotundata Cooper 
Foerste suggests that the Swift Current formation resembles the Tyrone of 
Kentucky but Kay refers it to the Chaumont division of the Black River. 
Cloche Island formation.—This formation is composed of 55 feet of light- 
gray, heavy-bedded limestone with shaly beds in the lower part. It occupies most 
of the southern part of Cloche Island and may extend to Delta County, Mich. 
Brachiopods listed by Kay and others are: 
Camerella panderi Billings =Idiospira panderi (Billings) 
C. volborthi Billings 
Dalmanella rogata (Sardeson) = Paucicrura rogata (Sardeson) 
Dinorthis sweeneyi (N. H. Winchell) 
Doleroides pervetus (Conrad) 
Glyptorthis bellarugosa (Conrad) 
Hallina sp. 
Hesperorthis tricenaria (Conrad) 
Rafinesquina alternata (Conrad) = Rafinesquina trentonensis (Conrad) 
“R.” inquassa (Sardeson) = Opikina inquassa (Sardeson) 
Rhynchotrema increbescens (Hall) 
Rostricellula rotundata Cooper 
Sowerbyella punctostriata (Mather) 
*Strophomena sp. S. emaciata Winchell and Schuchert 
*S. filitexta (Hall) 
Kay (1937, p. 257) correlates this formation with the Rockland of Ottawa 
and with the Guttenberg of the upper Mississippi Valley section. The fossils 
recorded above, if correctly identified, indicate that the Cloche Island formation 
may embrace a somewhat higher part of the Trenton as well. The Cloche Island 
on the chart is made equivalent to the Rockland of the Ottawa Valley, otherwise 
difficulties arise with the higher formations. All these faunas need revision. 
3. CHAMPLAIN, MOHAWK, AND HUDSON VALLEYS 
CHAMPLAIN VALLEY (WEST SIDE) 
In and about the village of Chazy, Clinton County, N. Y., on the west side 
of Lake Champlain, a considerable body of fossiliferous rocks, nearly goo feet 
on Valcour Island, has long been known as the Chazy limestone (here called 
