70 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



limestone. Rounded grains are evident in the samples, and ovules and 

 oolite occur at some depths. As to color, 1,475 feet is a decided gray 

 presenting a readily recognized contrast to 1,450 feet; from 1,500 feet 

 to 1,775 feet the material is pretty uniform in color, and would be de- 

 scribed as being light brownish gray, but dark brown spots due to iron 

 oxide occur at 1,600 feet; 1,800 feet is light brown with many white 

 particles (fossils, etc.) ; from 1,825 feet to 1,975 feet the samples are 

 light brownish gray with a yellowish cast, or are light yellowish brown 

 and contain more or less of the white particles. In all the samples there 

 is a trace, or a little more, of the fine angular quartz sand, together 

 with an occasional larger rounded grain. Determinable fragments 

 of organisms are few in all the samples and almost absent in some. 

 Foramiuifera are by far the most abundant recognizable fossils, and they 

 form a considerable percentage of the samples from 1,625 feet, 1,650 

 feet, and 1,775 feet. Textularia is the most numerously represented 

 genus, w T ith Orbitoides next. Amphistegina, Cristellaria, Orbitolites, and 

 other genera, are also easily to be found. Other classes of organisms are 

 not common, even lamellibranchs not being numerous except at 1,600 

 feet. Corals are uot abundant in any of the set, and seem to be entirely 

 lacking from many of them. 



2,000 feet. — At this depth the rock loses its yellowish cast and be- 

 comes a light brownish gray, contrasting somewhat with 1,975 feet. 

 The rock seems to have been a rather solid limestone with porous por- 

 tions. It was very fossiliferous, foramiuifera being especially abundant, 

 though other classes are well represented. The obtusely and the sharply 

 conical Textularias are the most numerous and Orbitoides seems to be 

 absent. 



Although the genus Orbitoides does not seem to be represented in the 

 samples from depths above 900 feet from the surface, except sparingly 

 at 800-850 feet, there seems to be no particular change in the rock until 

 after 700 feet has been reached, and there is a marked transition between 

 the sample from that depth and the one next above (675 feet). On ac- 

 count of these facts I am inclined to place the approximate upper limit 

 of the Vicksburg beds of the Eocene in this well at 700 feet below the 

 surface of the ground. The lower limit of the Vicksburg is not easily 

 made out. Orbitoides seems to lie the predominating foraminifer down 

 to 1,450 feet inclusive. Between this depth and the next (1,475 feet) 

 there is a decided change in color, and while Orbitoides d.>cs not dis- 

 appear entirely at once, the two conical forms referred to Textularia are 

 much more numerous. Below 1,875 feet Orbitoides seems to be lacking. 



