June 1G, 1905.] 



SCIENCE. 



931 



whether considered geologically or topograph- 

 ically, have a wide range. 



It is to be remembered, however, that mas- 

 sive-solid eruptions are but one phase of the 

 volcanic problem and, for their complete elu- 

 cidation, should not be rigidly separated from 

 other phases of the same process. 



Israel C. Russell. 



RECENT VERTEBRATE PALEONTOLOGY. 

 FOSSIL MAMMALS OF MEXICO. 



The mammalian paleontology of Mexico 

 offers a most interesting field for investiga- 

 tion, since it promises to reveal the southern 

 range of many North American Miocene and 

 Pliocene types, as well as the northern range 

 of South American types, Pliocene and Pleis- 

 tocene, in addition to many types which will 

 be found to be peculiar to Mexico. The lit- 

 erature of the subject is still quite limited, 

 including contributions by Richard Owen,* 

 by Professor Copef and a recent interesting 

 memoir by Dr. M. M. Villada,^ of the Na- 

 tional Museum of Mexico. 



In connection with the proposed visit of the 

 International Geological Congi'ess to Mexico 

 in the summer of 1906 the following cursory 

 notes may be of interest. 



The elephant remains in the National Mu- 



* Owen, R., 'On Fossil Remains of Equines from 

 Central and South America referable to Equus 

 conversidens Ow., Equus tau Ow., and Equus 

 arcidens Ow.,' Phil. Trans., 1869, pp. 559-573. 

 'On Remains of a Large Extinct Lama (Palau- 

 chenia magna Ow. ) from Quaternary Deposits 

 in the Valley of Mexico,' Phil. Travis., 1869, pp. 

 65-77. 



t Cope, E. D., ' Review of Dumeril et Bocourt's 

 Mission Scient. Mexique,' Amer. Nat., Vol. XVIII., 

 1884, p. IG'2. ' Gigantic Bird from Eocene of 

 ]\Iexico, Diatryana Gigantea,' Pr. A. N. 8., 1876, 

 p. 10. ' Extinct Mammalia of the Valley of 

 Mexico,' Proc. Am. Philos. Soc, Vol. XII., 1884, 

 117, p. 1. ' Report on Coal Deposit near Zaeualti- 

 pan, Hildalgo, Mexico,' Proc. A. P. S., XXIII., 

 122, 1885, p. 1. 'The Comision Cientifica of 

 Mexico,' Amer. Nat., XIX., 1885, p. 494. 



t Villada, Manuel M., ' Apuntes acerca de la 

 fauna fosil del Valle de Mexico,' Anales del Museo 

 Nacional de Mexico, T. VII., Entrega 14, Ma, 

 100.3. pp. 441-451, 8 pll. 



seum have usually been ascribed to Elephas 

 columhi; but they include molar teeth not 

 only of this species, but of the much larger 

 form, Elephas imperator. In the collection of 

 the Geological Survey of Mexico in the new 

 survey building are the skull and tusks of an 

 E. imperator of magnificent proportions, the 

 tusks measuring 5 m. 10 cm., or 16 feet 10 

 inches, in length; this specimen was secured 

 during the excavations for the great drainage 

 canal of the Mexican Valley. Owen's type 

 of Equus conversidens and Equus tau from 

 the valley of Mexico belong to the National 

 Museum, but are not at present accessible, 

 owing to changes in the building. There is, 

 however, the skull of a Pleistocene horse from 

 the valley of Mexico referred by Villada to E. 

 excelsus, but probably belonging to a distinct 

 and much more massive type of animal with 

 exceptionally powerful postorbital arches. 

 Here also is found the fine carapace of a 

 glyptodon {Glyptodon mexicanus) . 



The new building of the Geological Insti- 

 tute of Mexico is being pushed forward to 

 completion with a view to the visit of the 

 International Geological Congress. The di- 

 rector. Dr. Jose G. Aguilera, very kindly ex- 

 hibited to us the chief specimens of mam- 

 malian fossils. These include the skull of a 

 mastodon probably related to the South Amer- 

 ican M. humholtii, the palate and teeth of a 

 small variety of horse of the size of a donkey, 

 labeled by Castillo in 1866, but not yet de- 

 scribed. Besides the skull above noted there 

 are several single teeth of Elephas imperator, 

 molars of the M. humholtii type from Chiapas, 

 of the E. columhi type from the village of 

 Zacapu in Michoacan, of E. imperator from 

 the valley of Puebla. In a bed of lignites, 

 probably of Upper Miocene or Loup Fork age, 

 were found the types of Hipparion (= Proto- 

 hippus) castillei Cope, and teeth belonging to 

 Mastodon floridianus, also teeth of the peccary. 

 Also probably of Loup Fork age from the val- 

 ley of Toluca is the jaw of a rhinoceros, a very 

 short-skulled type, the canines being separated 

 by very short intervals from the premolars, 

 while the molar teeth are exceptionally long- 

 crowned. Very large horse teeth found in the 



