Geology and Paleontology. 



<£weral Notes. 



GEOLOGY AND PALEONTOLOGY. 



Fresh- Water Diatomaceous Deposit from Staked Plains, 

 Texas.— Some nearly white earth, very light in weight, from Crosby 

 County, Texas, and within the Staked Plains region was submitted by 

 Prof. E. D. Cope to the first of the undersigned authors for 



In a contribution to the " Vertebrate Paleontology of Texas," page 

 123 of the Proceedings of the American Philosophical Society, Prof. 

 Cope states that this material is from the Blanco Canon beds as 

 named by Mr. Cummins in the first annual report of the Geological 

 Survey of Texas, 1890, page 190, and describes it as a "white 

 siliceous friable chalk." 



Under the microscope this earth is found to be constituted almost 

 entirely of the siliceous skeletal remains of fresh-water diatoms, 

 probably 90 per cent, of the body of the earth being made up of these 

 minute single celled forms of plant life. The mass was disintegrated 

 and the diatoms separated and cleaned by J. A. Shulze after which 

 the forms were referred to C. Henry Kain for identification which he 

 has done with much care and after consultation with various authori- 

 ties, both by personal letter and through the medium of their 

 publications. 



He reports : " This is a fresh-water fossil deposit. The species con- 

 tained in it may now be found living in Utah and in the Yellowstone 

 Park. Many of the species are also common to fresh water streams 

 everywhere." 



The following number of species, twenty-seven in number, though 

 not exhaustive, is nearly so. 



Amphora ovalis Ehr. ; Amphora xincinatum Ehr. 1 ; Achnanthes ven- 

 tricosa Ehr. ; Campy lodiscus clypeus Ehr.* ; Cymbella cistula Hempr. ; 

 x T}iis is doubtless the form which Ehrenberg figures as Coeconema undnatum— 

 see Proc. Roy. Acad. Berlin, 1870, pi. 1 (II) fig. 9. It is however really an Amphora. 

 *In a preliminary list furnished by C. H. Kain, and published by Prof. E. D. Cope 

 in the paper before referred to (see page 123) this form is noted as C buo tutu , 

 having been wrongly identified before the cleaning of the material rendered the 

 markings plainly visible. 



