TEENTON PERIOD. 67 



Our specimen presents no material diiference from the figures and 

 description given by Edwards and Haime, and it evidently belongs to that 

 species. Their type-specimens were obtained by de Verneuil fi'om strata 

 of. the Trenton period in Ohio. 



Position and locality. — Strata of the age of the Trenton period; Silver 

 Canon, Palu'anagat range, Nevada. 



Genus FAVOSITES Lamarck, 1816. 

 Favosites (?). 



Among the collections are some specimens of Favosites that were 

 obtained from strata of the Cincinnati epoch, both at Silver City and Upper 

 Mimbres Mining Camp, New Mexico. They have been mostly silicified, 

 by which change their wall-pores and other minute details of structure 

 have been obliterated. 



The specimens have the general aspect of F. Gothlandica, and, indeed, 

 of several other admitted species also. But in view of the small number of 

 characteristics possessed by even well-preserved specimens of this genus 

 that may be relied upon for specific discrimination, and also of the imper- 

 fect condition of the specimens contained in the collections, no specific des- 

 ignation is given them. 



Family THECID^. 



Genus FAVISTELLA Hall, 1847. 

 Favistella stellata Hall. 



Plate IV, fig. 6 a, b, and c. 



Favistella stellata Hall, 1847, Paleontology of New York, i, 275. 



Columnaria alveolaf a Edwards et Haime, 1851, Monographie des Polyplers Fossile8,309. 



Favistella stellata Hall, 1862, Geol. Wisconsin, i, 430. 



avist ella stellata Dana, 1862, Manual Geol., 220 ; ib., 2d ed., 1874, 204. 



Coral foiTning an irregular compact or subhemispherical mass ; cells 

 varying in diameter from two to fom- millimeters, the average being about 

 three millimeters ; the number of sides of each cell also varying from four 

 to seven ; diaphragms numerous, flat, or nearly so, at their centi'al por- 

 tions, but are bent downward a little at their margins, where they join the 



