67 

 Ni/x^chia Brebissonia W. S. 



— spectabilis C. G. E. 

 Surirella Geroltii C. G. E. 



To these I bave to add for they occurs in my specimens. 



Navicula cuspidata F. T. K. 



Nit^schia {vitrea var.) salinariun A. G. 



Stauroneis punclata F. T. K. 



Synedra ulna P. A. C. N. 



There is present a small quantity of jagged siliceous particles of 

 lava, the same as is found ali over the bed of the Occidental Sea 

 and which carne from the volcanoes which opened when the sea 

 was raised and the country drained. Of course this occurs when 

 the Occidental Sea was formed as I theorize. But it was formed 

 in a long time and eruption of lava were formed several times, 

 in fact are now forming on the Great Plain as sbown by C. K. 

 Gilbert in a letter which 1 bave from him when discuss in the subject 

 of the Occidental Sea. 



In a specimen which was sent to me by M. Kennedy from 

 Mulberry canon, Texas, which is also from the Lano Estacado, I 

 found 



Amphora ovalis F. T. K. 



Cocconeis placentuìa F. T, K. 



Cymbella lanceolata C. G. E. 



Denticida palea P. A. C. N. 



This is in Denticula lauta of J. W. B. 



Epithemia Juergensii C. A. A. 



— gibba C. G. E. 



— gibberula C. G. E. 

 Fragilaria virescens T. R. 

 Gomphonema vibrio C. G. E. 

 Melosira granulata F. T. K. 

 Navicula affini s C. G. E. 



— ambigua C, G. var. craticula. 



— Brebissonii F. T. K. 



— viridis F. T. K. 

 NitT^schia scalaris C. G. E. 

 Synedra ulna P. A. C. N. 



