268 NEW YORK STATE MUSEUM 



Stropheodonta hunti nov. 



Shell small, regularly convexo-concave. Ventral valve most con- 

 vex along the median line, where the curvature is evenly arched 

 and well elevated ; lateral slopes depressed, at times slightly con- 

 cave. Hinge line long, straight, often with cardinal extensions; 

 the length of hinge is to the length of shell as three to two. The 

 surface of the valve is uniformly smooth, usually appearing nacre- 

 ous and without lineation but well preserved exteriors show an 

 extremely fine radial striation hardly visible to the naked eye. 

 About the umbo are a few low corrugations, three or four in num- 



~4 



skip 



P.1 WSSmM 



Stropheodonta hunti 



ber and these become extinct over the body of the valve. The 

 dorsal valve shows the same degree of corrugation as the ventral 

 and cardinal area of conjoined valves indicates nearly complete 

 closure of the delthyrium and a fine denticulation extending almost 

 to the cardinal angles. The species has been observed frequently. 



The shell suggests both in size and in the aspect of its nacreous 

 surface the well known S. n a c r e a from the Hamilton of New 

 York 1 for which Hall and Clarke introduced the subgeneric term 

 Pholidostrophia. 2 Other representatives of this group are known, 

 namely an undescribed shell from the Onondaga limestone of New 

 York and Ohio and probably the Strophomena lepis Bronn 

 of the Eifel Middle Devonic. 



Lower Devonic. Grande Greve, P. O. 



1 According to Schuchert this is the same shell as that described by Owen as Chonetes? 

 iowensis from the Middle Devonic ot Iowa and if this is the older species name it should 

 take precedence 



2 Palaeontology of New York, 1802, v. 8, pt 1, p. 287. 



