11 



OBSERVATIONS UPON THE GENUS RECEPTACU- 

 LITES, De France ; with notices of some new species : 



A characteristic fossil of the Lead bearing beds, was refer- 

 red by Dr. D. D. Owen in his Report on the Mineral Region 

 of the Northwest, in 1844, page 40, to Coscinopara sulcata, of 

 Goldfuss, and he gives a figure of the same, pi. 7, fig. 5. \t 

 is subsequently cited in his reports, and in the catalogue of 

 fossils accompanying the " Geology of Wisconsin, Iowa and 

 Minnesota," (his last report upon that region,) the name is con- 

 tinued. This fossil however is clearly a Receptaculites, and 

 must be referred to that genus, I propose for it the name 

 of Receptaculites Oweni. 



In the report first mentioned (of 1844,) Dr. Owen figures on 

 pi. 18, fig. 7, a fossil under the name of Orbitolites, reticu- 

 lata. This name is not continued in the final list; but from 

 similar specimens, I am constrained to refer this also to the 

 genus Receptaculites. In the report on the Geology of 

 Wisconsin, Iowa and Minnesota, 1852, page 586, Dr. Owen 

 describes, under Foraminifera, a new genus Selenoides, which 

 he says he at first supposed would be found to belong to the 

 genus Orbitulina. The following is the generic description 

 given page 586 : 



SELENOIDES (n. g.) 



Generic character. " It was supposed at first that this singu- 

 lar fossil from limestones of Lower Silurian date of Iowa, 

 would fall into the genus Orbitulina. But as D'Orbigny re- 

 gards this genus as an unequal-sided Orbitolites, in which one 

 side is convex, incrusted, and showing numerous cells in ob- 

 lique lines around the sides, it can hardly be grouped with it, 

 as the Iowa fossil is umbilicated on one side, and the cellular, 

 ring-shaped surface instead of being concave, is so convex as 

 to form nearly a coiled cylinder. The other side being partly 

 defaced in splitting it out of the rock, it is difficult to say 

 whether it had a cellular surface similar to that shown of fig. 

 13, Tab. II. B., or concentric lines ; what portion of it is visi- 

 ble rather indicates that the fossil was unequal-sided, not being 

 umbilicated on the other surface ; probably cellular, and not 

 without concentric lines. There are no cup-shaped cells open- 

 ing round the periphery, as in Orbitolites, which are said to 

 be equal-sided Orbitulinas." 



