94 THE PALEONTOLOGY OF MINNESOTA. 



[Protarifia. 



Section MADREPORARIA PERFORATA. 



Family PORITID^E. 





 PROTAREA VETUSTA Hall, sp. 



PLATE G, FIGS. 21," 25. 



1847. Porites? vetusta HALL. Palaeontology of New York, vol. i. p. 71, pi. 25, flg. 5a, 5b. 



1850. Astrceopora vetusta d'ORB'iGNY. Prodrome de Palcontologie. 



1851. Protarea vetusta EDWARDS and HAIME. Monograph Poly. Foss. desTerr. Pal., pi. 14, flg. 6. 

 1875. Protarea vetusta NICHOLSON. Palaeontology of Ohio, vol. ii, p. 221. 



1875. Protarea vetusta NICHOLSON. Paleontology of the Province of Ontario, p. 9. 



1882. Protarea vetusta HALL. Eleventh Kep. State Geologist of Indiana, p. 378, pi. 49, flg. 4. 



Original description. "A sub-hemispheric coral, composed of irregular concentric 

 laminae ; cells vertical to the laminae ; openings upon the surface, nearly circular, 

 with internal vertical lamellae which reach half way to the center." 



The following description is that of Nicholson (Pal. Ohio, vol. ii, p. 221): 



"Corallum forming thin crusts, about one third of a line in thickness, which 

 grow parasitically upon foreign bodies. Calices nearly equally developed, usually 

 hexagonal, about one line in diameter or rather less, shallow, the bottom of the cup 

 being tuberculated. Septa twelve in number, sub-equal, extending but a short dis- 

 tance inwards towards the center of the visceral chamber. Walls of the calices thick." 



Mr. Ulrich has a specimen of this species from the upper layers of the Trenton 

 shales of "St. Anthony hill," St. Paul, Minnesota. He writes us that the specimens 

 from the Cincinnati group and identified with this species have larger calices than 

 those collected by him from the Trenton at Pauquette Rapids, Canada, which are, 

 undoubtedly, like the specimen from Minnesota. If this difference is a specific one, 

 which is very probable, then the specimens from the Hudson River group and 

 referred to this species should be distinguished by another name. It may be that 

 this is the form named in 1851 by Edwards and Haime, Protarea verneuili (Pol. Foss. 

 des Terr. Pal., p. 71.) 



Formation and locality. A single specimen of this species has been found in the Hudson River 

 group at Spring Valley, Minnesota, upon a fragment of a species of Rajinesquina. It is also found in the 

 upper portion of this group at Richmond, Indiana; Oxford, Waynesvillc, etc , Ohio, and Wilmington, 

 Illinois. In the lower portion of the Trenton formation at Watertown, New York ; Peterboro and near 

 Ottawa, Canada, and St. Paul, Minnesota. 



Mus. Reg. No. 7725. 



