44:4 University of California Publications in Geology [Vol. 7 



the Mohave River two miles southeast of Manix ; the name Manix 

 Beds is therefore proposed for them. The Pleistocene lake in 

 which they were deposited will be referred to as Manix Lake. 



The Manix Beds were brought to the attention of the writer 

 by Mr. H. S. Mourning of Los Angeles, who had learned of the 

 occurrence of vertebrate fossils in this formation from Mr. John 

 T. Reed of San Bernardino. The writer is indebted to Professor 

 John C. Merriam for the opportunity of engaging in the exam- 

 ination and for subsequent advice and criticism. 



No reference to Pleistocene lake-beds in this region has been 

 found in the literature. Some of the ranges surrounding the 

 basin containing the Manix beds have, "however, received some 

 attention from geologists. Lindgren, 1 Storms,- Campbell, 3 

 Keyes, 4 Baker, 3 and others have studied the geology of the 

 Calico Mountains to the west, and Storms 6 has published a brief 

 account of the gold-bearing rocks of the Alvord Mountains to 

 the north. 



The geologic results offered in this paper are to be considered 

 as of no more than reconnaissance value, inasmuch as a large 

 part of the time spent in the region was occupied in searching for 

 vertebrate fossils in the lacustral beds. 



General Geographic and Geologic Features of the Region 



The Manix Lake basin lies about 120 miles northeast of Los 

 Angeles, and twenty to forty miles east of Barstow, California. 

 It is traversed by the lower course of the Mohave River, an inter- 

 mittent stream which rises on the higher, less arid north slopes 

 of the San Bernardino Mountains. After leaving the mountains 



1 Lindgren, Waldemar, The silver mines of Calico, California, Trans. 

 Am. Inst. Min. Engineers, vol. 15, pp. 717-734, 1887. 



2 Storms, W. H., Report on San Bernardino County, in 11th Ann. (1st 

 Biennial) Report of the State Mineralogist, Calif. State Min. Bureau., pp. 

 337-369, 1893. 



s Campbell, M. R., Reconnaissance of the Borax Deposits of Death 

 Valley and Mohave Desert, U. S. Geol. Surv., Bull. no. 200, pp. 12-13, 1902. 



1 Keyes, C. R., Borax deposits of the United States, Trans. Am. Inst. 

 Min. Engineers, no. 34, pp. 867-903, 1909. 



s Baker, C. L., Notes on the later Cenozoic History of the Mohave 

 Desert Region in Southeastern California, Univ. Calif. Publ. Bull. Dept. 

 Geol., vol. 6, no. 15, p. 349-353, 1911. 



o Storms, W. H., loc. cit. 



