3 Acer. 



Acervularia davidsoni. Edwards & Haime. From Col- 



hLmi 



m^^^^' p\.4-9.n 



lett's Indiana Keport of 1881 (Van Cleve), page 386, plate 49, 



fig. 2. Upper view of corallum, showing calices of the corallites ; 



sometimes the mass is a foot in diameter, usually much less. 



VIII^ Devonian of Indiana; common in Michigan and Iowa. 



Acervularia rugosa (Astrwa rugosa), Hall, 1843, page 159, 



Vflf.n. fig- ^2. 2. Cyathophyllum ru- 



Art^S^K^^^^ 9^^^^'^ S. A. Miller's cata- 



logue. Upper Helderberg (On- 

 ondaga) limestone, VIII^ a. 



Note. — This is probably the 

 Acervularia ch'^racteristic of the 

 Lewistown limestone (VI) and 

 abundant in the lowest beds (for 

 50 feet) in Huntingdon county, 

 Pa., Report T, p. 41 ; also in the 

 same beds overlying the Water 

 lime beds, in the Aughwick val- 

 ley section, Report T3, p. 126 ; 

 also, 0. E. Hall's collections of 

 1875 near Orbisonia. 



