306 

 LAMELLIBRAN CHIATA. 



EOPTERIA RlCHARDSONI. (N. Sp.) 



Fig. 298. 

 Fig. 298. — Eopteria Ricfiardsoni. a, left valve; 6, cardinal view. 



Description. — Shell obliquely sub-circular, length and width about 

 equal, uniformly convex ; anterior cardinal angle compressed ; beaks 

 small, closely incurved, situated a little behind the mid-length of the hinge 

 Ime ; surface with fine radiating strire. 



The only specimen collected is imperfect, but, it appears, that the whole 

 of the ventral and posterior margin is broadly rounded. Both valves are 

 equally convex, most tumid a little above the middle. The anterior car- 

 dinal angle is compressed and apparently rectangular or perhaps a httle 

 rounded. The jiosterior angle is not distinctly seen, but it seems to be 

 scarcely at all compressed. The hinge line behind the beaks is exhibited 

 as a rounded ridge with no evidence of a suture, (at least none can be 

 seen in this specimen). There are about six striae in the width of one 

 lino near the mai'gin. 



Uoptn-ia tijpica (^ante, p. 221,) has coarse ribs and is narrowly rounded 

 at the lower posterior angle. 



Length and width about 'J lines. 



Dedicated to the discoverer. 



Locality and Formation. — Near St. Antoine above Quebec, in a 

 boulder with Siibulites Psyche; Quebec group. 



Collector. — J. Richardson. 



