no SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 64 



The tubes are nearly circular in outline and probably grew in a 

 large frond on the bed of the body of water in which the algse lived. 

 The tubes are now filled with dark greyish-blue limestone. 



Genotype. — Copperia tuhiformis, new species. 



Stratigraphic range. — Lower portion of Xewland limestone 



Geographic distribution. — Eastern slope of Big Belt Mountains, 

 Montana. 



Observations. — At first I was inclined to place this form under 

 Greysonia, but from the form of the tubes and the irregular habit 

 of growth concluded to give it a distinct generic designation. 



COPPERIA TUBIFORMIS, new species 



Plate 19, figs. 1-3 



The principal characters of the species are given under the generic 

 description. The largest fragment in the collection has a length 

 of 15 cm. The tubes are from 7 to lo mm. in diameter and the 

 thickness of the layer made up of layers of the tubes is 6 cm. 



Formation and locality. — (400c) Algonkian, Beltian series: New- 

 land limestone; eastern slope of Big Belt Alountains, 8 miles (12.8 

 km.) west of White Sulphur Springs, at forks of Birch Creek, 

 IMeagher County, Montana. 



COLLENIA, new genus 



More or less irregular dome-shaped, turbinate or massive, lami- 

 nated bodies that grew with the arched surface uppermost. The 

 growth appears to have been by the addition of external layers or 

 lamellae of varying thickness with interspaces that vary greatly 

 even in the same specimen. 



Genotype. — Collenia undosa, new species. 



Stratigraphic range. — The type species occurs in the Spokane 

 shales of the Big Belt series of Montana. 



Collenia compacta, new species, is from the Siyeh limestone and 

 several thousand feet above the horizon of Collenia undosa. 



Collenia occidentale (Dawson) is from the Chuar terrane of the 

 Grand Canyon, where it ranges through 1.500 feet (460 m.) of 

 strata. 



Geographic distribution. — Eastern slope of the Big Belt Moun- 

 tains, south of White Sulphur Springs, Meagher County, Montana. 

 Gunsight Pass, Glacial National Park, Montana. Chuar \'alley in 

 the Grand Canvon, Arizona. 



