60 PHYSIOGRAPHIC GEOLOGY. 



todus, and South Africa has 1 species of Protoptei'us : in all not a dozen species of a tribe 

 that was once very prominent. Pelagic fishes occur at all depths to nearly 18,000 feet. 

 The " Albatross" brought up a Cyclothone from a depth of 17,094 feet (Agassiz). The 

 species of the deeper waters are described as having the bones feebly calcareous, being 

 slender and loosely connected, and some species will take in a fish for food three times as 

 large as themselves. Many kinds are phosphorescent. 



Cestraciont Sharks, once very numerous in species, are now but 4 in number, and all 

 are of one genus, Cestracion. These are confined to the coast regions between Japan and 

 Australia or New Zealand. The type has therefore nearly reached extinction. 



From the facts reviewed with regard to marine life, it is apparent that the knowledge 

 of depths and temperatures of living species affords little help for conclusions about the 

 habits of ancient species. Many of the tribes that were represented by warm-water 

 species and those of shallow seas, have now species that have become accustomed to great 

 depths and cold temperatures. Modern Brachiopods are no criterion for the ancient ; nor 

 modern Crinoids, nor modern Corals. 



Hot-water Life. 



In the north point of Owen's Valley, California, according to Dr. H. C. Wood {Am. 

 Jour. Sci., 1868), at 120° F., and also at 160° F. (as learned from Mrs. Partz), occur Algae, 

 some growing to a length exceeding 2 feet. The species is named Nostoc calidarium. At 

 the Hot Springs (" Geysers"), on Pluton Creek, California, Professor William H. Brewer 

 observed Confervse in waters heated to 140°-149° F. , and simpler Algse where the tem- 

 perature was 200° F. At the same place, Dr. James Blake found 2 kinds of Confervse 

 in a spring of the temperature of 198°, and many Oscillatorise and 2 Diatoms, in one of 

 174°. In the waters of Pluton Creek, of 112° F. , the Algse formed layers 3 inches thick. 

 Dr. Blake also collected 50 species of Diatoms from a spring in Pueblo Valley, Nevada, 

 the temperature being 163° F. ; and they were mostly identical with those of beds of 

 infusorial earth in Utah. At San Bernardino, California, William P. Blake found living 

 ConfervsB in water at a temperature of 130°. At Camiguin Island, east of Cebu, Moseley 

 found living Algse at 113^° F. ; and W. T. T. Dyer has reported that Oscillatorise have 

 been observed growing at 178° to 182° F. 



The various hot springs of the several Geyser Basins, in the Yellowstone National Park, 

 contain very various Confervoid forms. The hottest springs, up to 200° F., contain numer- 

 ous long, slender, white and yellow vegetable fibers, of undetermined relations, waving in 

 the boiling eddies, and becoming buried in the siliceous deposits over the bottom, where 

 they often form layers several inches thick. The bright green forms appear to be confined 

 to lower temperatures. W. K. Taggart reports that, at the vents on the shores of Lewis's 

 Lake, leafy vegetation is limited to temperatures below 120° (Hayden's Reports, 1871-2). 

 Dr. Josiah Curtis found, in these hot springs, siliceous skeletons of very numerous Dia- 

 toms ; but the vegetable matter ivas wanting in all cases where the temperature exceeded 

 96° F. So many different causes might introduce these skeletons to the hotter pools, that 

 their presence has not necessarily any more significance than that of the Grasshoppers and 

 Butterflies which are frequently found in the same pools. — Of animal life, living larves 

 of Helicopsyche were found, by Mr. Taggart, in a spring having the temperature, of 108°, 

 into which, however, they might have crawled from the river, which was close by ; so that 

 the eggs were not necessarily laid at the temperature given. 



At Banos, on Luzon, Philippine Islands, the author observed feathery Confervse in 

 waters heated to 160° F. In springs in the Pa^s^of Chivela, having a temperature of 

 98° F., the United States Exploring Expedition of 1872 found Fish; and, according to 

 Mr. James Richardson, Fish occur in springs in Marocco having a temperature of 75° F. 



On the subject of the geographical distribution of animals, the most important works 

 are Wallace's work in 2 volumes under this title, and his Island Life; and on North 

 America, J. A. Allen, 1892, Bulletin American Museum, New York. 



