109 



upon the sandstone apparently, I often found layers of a yellowish, 

 white rather soi't limestone, fully charged with Inoceramas problemati- 

 cus and fish remains. Near Sioux City, about two miles below the 

 mouth of Big Sioux river, is a vertical section of No. 1, rising about 

 thirty feet above the water's edge. At the base of this vertical cut I col- 

 lected a number of leaves, similar to those observed at Blackbird Hill. 

 From the high bluffs, bordering upon the Missouri, the inhabitants of 

 this region obtain immense quantities of the calcareous rock of No. 3, 

 composed almost entirely of /. problematicus, and convert it into lime. 

 On the Big Sioux river, about six miles above its mouth, I took the 

 following section of the strata from a vertical cut with consi'derable 

 care. Yellow marl, a recent deposit. 



No. 3. Shaly limestone, gradually passing into bed below, with an 

 abundance of Inoceramas prohlemaiicus, and fish remains. 



No. 2. Dark plastic shaly clay, with ferruginous concretions. 



No. 1. a — Yellow friable sand. 



h — Earthy lignite, 6 inches. 



c — Variegated sandstones and clays, extending to water's 

 edge, with Dicotyledonous leaves. 



Section near the mouth of Iowa creek. 



No. 3. Gray and yellow marl, with immense numbers of /. prohle- 

 maficus, Osfrea congesta, and fish remains. 



No. 2. Dark plastic clay with Am7)ion{fes resting concordantly upon 

 the bed below. 



No. 1. Sandstone just above water edge. 



At this last locality I found in No. 1 the plant which Prof. Heer 

 refers to, Laurus primigenia, and a bhell which we have described as 

 Solen Dakotaensis. Here No. 1 passes from sight beneath the well 

 known cretaceous bed No. 2. 



With regard to our No. 1 holding a position beneath well marked 

 cretaceous beds, I think I need not say anything further. 



Poleontological evidence. 



The fine series of fossil plants from No. 1, which I collected on the 

 Missouri, as well as those obtained by my friend, Mr. Meek, and my- 

 self, during our recent trip to Kansas, were placed in the hands of our 

 friend. Dr. J. S. Newberry, the well known authority in fossil botany, 

 and from him we received the following notes :* 



"They include so many highly organized plants, that were there 

 not among them several genera exclusively cretaceous, I should be 

 disposed to refer them to a more recent era." 



" A single glance is sufficient to satisfy any one they are not 

 triassic. tip to the present time no angiosperm dicotyledonous 

 plants have been found in rocks older than cretaceous, while of the 

 eighteen species which comprise your collection, sixteen are of this 

 character." 



The species of y ur fossil plants are probably all new, though gen- 



* Dr. Newberiy' s remarks will appear in the January number of Silliman's Journal with 

 our joint paper. 



