56 PROCEEDINGS OF THE ACADEMY OF 



in the Scouleri. Its stylets are also flattened and carinated, instead of being 

 rounded. From Portlock's C. Colei it will be distinguished by having the 

 carina? of its stylets and telson smooth, instead of crenate. 



So far as we are informed, this is the first species of this genus found in 

 America. It is another decidedly Carboniferous genus, found in our Coal 

 Measures, directly associated with numerous fossils that occur in the beds on 

 the Missouri, in Nebraska, that have been wrongly referred by some authors 

 to the Permian (Dyas). 



Locality and position. Near the middle of the Coal Measures at Danville, 

 Illiuois, associated with numerous Upper Coal Measure species. 



Descriptions of FOSSILS collected by the TJ. S. Geological Survey under 

 the charge of Clerence King, Esq. 



BY F. B. MEEK. 



Washington City, March 21st, 1870. 

 Pkof. Joseph Leidt. 



Dear Sir, I send herewith, to be presented for publication in the Proceedings of the 

 Academy, descriptions of a few of the fossils brought in by the United States Geological 

 Survey under the direction of Clerence King, Esq. You will please state, in presenting 

 the paper, that the Trilobites described in it from Eastern Nevada, are decidedly Primor- 

 dial types, and, so far as I know, the first fossils of that age yet brought in from any loca- 

 lity west of the Black Hills. Mr. King's collections also establish the fact that the rich 

 silver mines of the White Pine district occur in Devonian rocks, though the Carbonife- 

 rous is also well developed there. The Devonian beds of that district yet known by their 

 fossils, seem mainly to belong to the upper part of the system. Mr, King, however, has a 

 few fossils from Pinon Station, Central Nevada, that appear to belong to the horizon of 

 the Upper Helderberg limestone of the New York series. 



The Tertiary fossils described in this paper, from the region of Hot Spring Mountains, 

 Idaho, came from an extensive and interesting fresh-water Lacustrine deposit, and are all 

 distinct specifically, and some generically, from all the other Tertiary fossils yet brought 

 from the far west. Two of the species belong to the existing California genus Carinifex, 

 or some closely allied group, while another beautifully sculptured species was thought, 

 by Mr. Tryon, to whom I sent a specimen of it, to be possibly a true Melania, and allied to 

 existing Asiatic forms. 



It is an interesting fact, that among all of our fresh-water Tertiary shells from this dis- 

 tant internal part of the Continent, neither the beaks of the bivalves, nor the apices of the 

 spire in the univalves, is ever in the slightest degree eroded; even the most delicate 

 markings on these parts being perfectly preserved, if not broken by some accident. From 

 this fact it may be inferred that the waters of the lakes and streams of this region, dur- 

 ing the Tertiary epoch, were more or less alkaline, as is the case with many of those 

 there at the present day. 



These descriptions, as well as others that I expect to send you soon, are merely prelim- 

 inary and will be re-written, and presented with full illustrations, now in course of prepa- 

 ration, in Mr. King's report of his survey. 



Very respectfully yours, 



F. B. MEEK. 



Tertiary Species. 



Sphjerium rugosum, Meek. 



Shell of medium size, rather gibbous, moderately thick, quadrato-suborbic- 

 ular in outline, the length being a little greater than the height; greatest con- 

 vexity slightly above the middle; anterior margin more or less regularly 

 rounded; base semielliptic in outline; posterior margin generally a little 

 wider than the anterior, and faintly subtruncate with an anterior slope; dor- 

 sal outline rounding into the anterior and posterior margins, but more regu- 

 larly into the former. Beaks not eroded, nearly central, rather prominent and 

 incurved, but not oblique. Surface ornament-d by sharply defined, often ele- 

 vated, concentric striae, separated by rounded furrows, in which very minute 

 lines of growth may be seen under a magnifier; the elevated concentric striae 

 becoming more regular, coarser, more distantly separated, and more promi- 

 nent on the umbones. Cordinal margin and lateral teeth comparatively 

 stout, 



[April, 



