708 



SCIENCE 



[N. S. Vol. XLIV. No. 1142 



J. J. Tanzola, of Columbia University, in the 

 U. S. Naval Academy, and Dr. C. H. Forsyth, 

 of the University of Michigan, in Dartmouth 

 College. 



Dr. Chas. H. Otis has resigned his position 

 as instructor in botany and assistant botanist 

 at New Hampshire College and Experiment 

 Station, to accept a position in the biological 

 laboratory at Western Reserve University. 

 Dr. Otis will have charge of the instruction in 

 botany in Adelbert College and the College for 

 Women, taking the place of Dr. Wm. H. Wes- 

 ton, who recently resigned. 



Mr. Paul C. Graff has been appointed in- 

 structor in botany at the University of Mon- 

 tana. 



DISCUSSION AND CORRESPONDENCE 



FURTHER EVIDENCE BEARING ON THE AGE OF 



THE RED BEDS IN THE RIO GRANDE 



VALLEY, NEW MEXICO 



The almost total lack of invertebrate fossils 

 in the Eed Beds exposed on the eastern side 

 of the Eio Grande Valley has made it very 

 difficult to determine their exact position in 

 the geologic column. In some localities defi- 

 nite determinations have been made, largely 

 upon stratigraphic evidence, showing that the 

 red sandstones and shales occur at horizons 

 ranging from the Upper Pennsylvanian to the 

 Cretaceous. The work upon this region has 

 been reviewed by Lee and Girty. 1 



During the last summer, while engaged in 

 a survey of the Permo-Carboniferous boundary 

 line for the Carnegie Institution, the writer 

 was able to spend a short time in the Red Beds 

 near Socorro, New Mexico. The examination 

 was made possible by suggestions and maps 

 furnished through the kindness of Dr. N. H. 

 Darton, of the U. S. Geological Survey. 



Two or three miles north of Carthage, New 

 Mexico, the prominent ridge of Dakota sand- 

 stone is underlain by a series of shales and 

 sandstone varying in color from bright green 

 to brilliant red with a few patches of con- 

 glomerate and impure limestone of limited 



i Lee, W. T., and Girty, Geo. H., ' ' The Manzano 

 Group of the Kio Grande Valley, New Mexico," 

 Bulletin 389, TJ. S. Geological Survey, 1909. 



horizontal extent. The arid valley between 

 the ridge and the hills to the north capped 

 by the San Andreas limestone affords an ex- 

 cellent exposure of the beds. 



Lee and Girty reported a few doubtful in- 

 vertebrate fossils from the San Andreas at 

 this place and speak of 200 feet of red beds 

 overlying the limestone at the old lime kiln 

 near Carthage. 



No fossils were found in these upper beds and 

 their age is a matter of conjecture. 



They also report the Abo and Teso forma- 

 tions as present, but the exact locality of their 

 section is not given. The red beds above the 

 San Andreas limestone are faulted down 

 against it just at the old lime kiln and can be 

 traced up the valley for several miles. Close 

 to the lime kiln and about half way up to the 

 base of the Cretaceous the writer found a small 

 bed of conglomerate containing an abun- 

 dance of lamellibranchs in a very small patch. 

 These have not yet been identified. 



A few fragments of bone were found in the 

 same bed and further up the valley, but at a 

 lower level, other fragments were found. The 

 following list shows them, and the containing 

 beds, to be clearly Triassic. 



1. A small section, about four inches, of the 

 snout of a slender-jawed Phytosaur, suggest- 

 ing Angistorhinus or Mystriosuchus, with 

 teeth diverging at an angle of 15 to 20°. 

 This was found in a concretion in a dark 

 brown, impure limestone occurring as a lens 

 in the red shale. . 



2. Three vertebrse, found at different local- 

 ities, apparently Phytosaurian. 



3. The proximal and distal ends of a large 

 limb bone, badly worn and unidentified, but 

 certainly not related to any of the known 

 forms of Permo-Carboniferous vertebrates. 



4. Two small dorsal plates. One with a 

 median dorsal ridge and the other, regularly 

 hexagonal and with a ventral rugosity evi- 

 dently for attachment to the dorsal spine of a 

 vertebra. 



5. Several imperfect ends of large limb 

 bones; two suggesting the ends of a tibia and 

 a radius respectively. 



6. Two fragments of thoracic plates. One 



