30 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
Chaumont formation.—In the Crown Point section (Raymond, 1902, p. 21), 
Kay (1937, p. 259) states that beds 19 to 23 should be assigned to the Chaumont. 
The thickness is about 26 feet. Raymond records the following brachiopods. 
Dalmanella subaequata pervetus = Doleroides pervetus (Conrad) 
Hesperorthis ? costalis (Hall) ? 
*Plectorthis plicatella (Hall) 
*Rafinesquina alternata (Conrad) 
*Rhynchotrema inaequivalve (Castelnau) 
*Strophomena incurvata (Shepard) 
Zygospira recurvirostris (Hall) 
Some of the above brachiopods are undoubtedly incorrectly identified, but it 
is not possible to make revision without studying a collection from this forma- 
tion. Rafinesquina is generally absent from the Chaumont. If the fossils are 
correctly identified the limestone might be assigned to the overlying Amsterdam 
formation. 
Amsterdam formation.—According to Kay (1937, p. 259) beds 24 and 25 
of Raymond’s Crown Point section plus the lower 4 feet of bed 26, about 17 feet 
in all, belong to the Amsterdam formation of Cushing which is better displayed 
in the lower Mohawk Valley. The following brachiopods are reported by 
Raymond: 
*Dalmanella testudinaria = Paucicrura ? sp. ? 
*Dinorthis pectinella (Emmons) 
Plectorthis plicatella (Hall) 
Rafinesquina alternata (Conrad) = Rafinesquina trentonensis (Conrad) 
*Strophomena incurvata (Shepard) 
Zygospira recurvirostris (Hall) 
If the brachiopods recorded above are correctly identified, assignment of this 
manifestation of the Amsterdam formation to a position equivalent to high 
Decorah (Ion) would be necessary, but this is not in accord with faunas of 
overlying formations. 
Isle la Motte formation.—Kay (1937, pp. 259, 260) assigns the remainder 
of bed 26 and beds 27 and 28, about 16 to 20 feet of limestone, to the Isle la Motte 
formation. At the type section this is 10 feet of black, gray-weathering, heavy- 
bedded limestone. This formation extends to the south to the vicinity of Glens 
Falls, N. Y. Brachiopods listed by Raymond are: 
Dalmanella testudinaria = Probably Paucicrura 
Dinorthis pectinella (Emmons) 
Glossina trentonensis (Conrad) 
Rafinesquina alternata (Conrad) = Rafinesquina trentonensis (Conrad) 
Strophomena incurvata (Shepard) 
Triplecia extans (Emmons) = Triplesia cuspidata (Hall) 
Correlation of Isle la Motte formation.—Kay (1937, p. 261) correlates the 
Isle la Motte formation with the Rockland of Ontario because of Triplesia and 
other fossils such as Maclurites logani and Colwmnaria hall. If the recognition 
of these formations in the Crown Point section is correct the position of the 
Amsterdam formation is made clear between the Chaumont and Isle la Motte. 
