651 



Placu. 



Placunopsis carbonaria, Meek and Worthen Proc. Chi. 



Meek and Vil. GtoUlllnois 



Acad. Sci. 1866; Geo. Sur. 111., Vol. 5, 1873. p. 578, pi. 27. fig. 

 2(35, upper (right) valve broken in places, but showing the pecu- 

 liar transverse costae crossing the umbo often seen on this 

 species, as well as the radiating ribs (costae), concentric mark- 

 ings, etc. ; 25, a smaller specimen of the same valve ; 2c, a 

 large specimen of this species (?) with much less prominent 

 beak (umbo) and straighter hinge-edge; 2rf, small internal 

 cast. (Genus Placunopsis founded for shells of the Great 

 Oolite formation ; never found earlier ; yet these high Coal 

 measure specimens agree so perfectly, as to be identifiable with 

 Koemer's type, P. jurensis^ except for the cross lines. (M. & 

 W.) Springfield, 111. upper part of Coal Measures. XV^ XVI? 

 Placunopsis recticardinalis. Meek. Pal. Ohio, Vol. 2, 



>(IJWcJ^ife^_ #/2 ^^'^^^ P^g^ ^^1' P^^^^ 1^9 fig- 1^9 ^^ inter- 

 nal cast of (apparently) the left or upper 

 valve showing the very curious markings 

 peculiar to this genus of shell, named by 

 Morris and Lycett in 1853, among the fos- 

 sils of the English Oreat Oolite^ because 

 ^-««ss^^i- -w^ . ^^ ^^^ resemblance (opsis) to the genus 

 ^'•^'^'^i^^^J^^H Placuna. S. A. Miller gives only two 

 American species, P. carhonaria^ M. & W. Upper Coal meas- 

 ures of Illinois ; and this '' straight-hinged " Placunopsis of the 

 Ohio Coal measures. XII L 



Planocephalus aselloides, Scudder. An insect found in 



'^- the Oligocene tertiary beds of 



Florissant, Colorado. Figure 972 



{magnified three times) ^ restored^ 



zihrei 972 and Section, in ZittePs Handbuch. 



Terh 



