174 Tertiary. 



in Nebraska, in the vicinity of Peno creek, a small tributary of Teton, 

 or Little Missouri river, in a thin bedded, light gray, siliceous^ lime- 

 stone, near the summit of the elevated plateaux which border the 

 Mauvaises Terres, Planorhis nebrascensis, LiiniKBn diapliana, L. ne- 

 brascensis, Physa secalina, and Cypris leidyi. 



T. A. Conrad* described, from the (Jackson Group) Greensand 

 Marl-bed of Jackson, Mississippi, Astarte parilis, Umbrella planulata, 

 Gorbula bicarinata, C. densata, Leda muUilineata, now Huculana 

 multilineata, Wavicula aspera, Crassatella jlexura^ Glossus Jilosus, 

 now Axincea filosa, Ostrea trigonalis, Pecten nuperus, Capiilus ameri- 

 canus, Clavelithes humerosus, C. varicosus, C. mississippiensis, now 

 PapilUnamississippiensis, Trochita alta, Mitra dumosa, nov^ Lapp aria 

 dumosa, Conus tortilis, VolutlUthes symrrtetricus, V. dumosus, Rostella- 

 ria velata, now Calyptrophorus velatus, B. 8taminea, now C. stamin- 

 eus, Caricella subangulata, C. poh'ta, JVatica permunda, Bostellaria 

 extenta, now Platyoptera extenta, Mitra millingtoni, now Fusimitra 

 millingtoni, Teredo mississippiensis, Architectonic a acuta, A. belUstri- 

 ata.^ Cyprcea pinguis, C. fenestralis, Gastridium vetustum, Phorus 

 reclusus, Turritella alveata^ Galeodia petersoni, and Strepsidura du- 

 mosa. 



Dr. J. W. Duwson,f describing the drift of Nova Scotia, in 1855, 

 said, that in the low country of Cumberland there are few bowlders, but 

 of the few that appear, some belong to the hard I'ocks of the Cobequid 

 hills to the southward; others may have been derived from the some- 

 what similar hills of New Brunswick. On the summits of the Cobe- 

 quid hills, and their northern slopes, we find angular fragments 

 of the sandstones of the plain below, not only drifted from their orig- 

 inal sites, but elevated several hundreds of feet above them. To the 

 southward and eastward of the Cobequids, throughout Colchester, 

 Northern Hants, and Pictou, fragments from these hills, usually much 

 rounded, are the most abundant traveled bowlders, showing that there 

 has been great driftage from this elevated tract. In like manner, tlie 

 long ridge of trap rocks, extending from Cape Blomidon to Briar Island, 

 has sent off great quantities of bowlders across the sandstone valley 

 which bounds it on the south, and up the slopes of the slate and granite 

 hills to the southward of this valle3^ Well characterized fragments of 

 trap from Blomidon may be seen near the town of Windsor, and un- 

 mistakable fragments of similar rock from Digby neck, on the Tusket 

 river, ma^^ be seen, thirty miles from their original position. On the 



'•• Wailes' Geo. of Miss, 

 t Acadian Geology. 



