320 /Scientific Intelligence, 



and south by the Orinoco, and Rio Negro is covered by crystal- 

 line rocks, which are partly or wholly Archaean. North, west and 

 south of the area the color on the map is that of the Tertiary and 

 Quaternary over a wide region extending to the base of the 

 mountains. Then follows a belt of Cretaceous, either side of 

 narrow ranges of crystalline rocks, with Jurassic beds only over 

 a small area east of Popayan in the U. S. of Colombia (New 

 Grenada). Beyond these crystalline ranges westward there are 

 Quaternary belts along the Magdalena and Oauca Rivers and 

 over a shore region, with intervening belts of crystalline rocks 

 bordered by Cretaceous. No rocks of the Triassic or Carboni- 

 ferous series, or of any Paleozoic formations, have been recog- 

 nized, the reports respecting the occurrence of such rocks being 

 errors. The map and the profiles also illustrate the positions of 

 the volcanic cones and areas. The descriptions of the Cretaceous 

 fossils figured were published by the author in the Amtlicher 

 Bericht der Naturforscher-Versammlung in Wien, 1858. 



3. Fossil Sponges and Plants. — Sir Wm. Dawson has a paper 

 on some remarkable hexactinellid sponges from Little Metis, near 

 Quebec, of the age of the Chazy, in the Transactions of the Royal 

 Society of Canada, iii, 1889, with figures. The paper has notes 

 on the species by Dr. G. P. Hinde. The same volume contains 

 also a paper by the same author giving descriptions of figures of 

 fossil plants from Mackenzie and Bow rivers. The Mackenzie 

 River plants are from the " Upper Laramie or Fort Union Group," 

 <6 still held by some paleontologists to be Miocene," equivalent of 

 beds in Greenland, Alaska, etc. 



4. Emanations of carbonic acid, sulphurous and other gases 

 at ''Death Gulch" Yellowstone Park. — Mr. W. H. Weed, of the 

 U. S. Geological Survey, has described in Science, of February 

 15th, 1889, the "Death Gulch" in the extreme northeastern por- 

 tion of Yellowstone Park, on Cache Creek, two miles above its 

 confluence with Lamar River, five miles from the mail station of 

 Soda Butte. In an opening bordering on Cache Creek occur evi- 

 dences of former hot springs in geyser-like deposits, a hot spring 

 cone half washed away, a mound of travertine, and a little tepid 

 sulphurous water at the edge of the stream. Besides, there are 

 copious gaseous emanations rising through the waters of the 

 creek " mainly, no doubt, carbonic acid, although containing 

 some sulphuretted hydrogen." Above these is altered and crys- 

 talline travertine, besides a bank of sulphur and gravel cemented 

 by travertine. In a lateral gully, the waters of its small stream, 

 sour with sulphuric acid, flow in a channel cut through beds of 

 dark gray volcanic tufa. The only springs now flowing are oozes 

 of water, forming a creamy white deposit about the vents which 

 is largely an alum (alumina sulphate). The odor of sulphur is 

 strong. The bears and other wild animals of the region are 

 often killed by the gases. Dead bears were found in all stages 

 from skeletons to freshly killed, and with them were remains of 

 an elk, squirrels, rock-hares, etc., and many dead butterflies and 

 other insects. 



