SWALLOW AND HAWN—THE ROCKS oF KANSAS. 191 
posterior acne marked with fine distinct concentric strie 
and large irregular lines of growth; cardinal line straight, or 
. “Tenet 0.68; convex; anterior extremity rounded. 
Canorowonrns (?) RHoMBomEA, Swallow. 
Shell _inequilateral, transversely elongated, ‘Sititac, oe 
, gibbous hee the beaks to the ventral posteri 
en 
4 li 8 , 
le; bea Le urved, i inclined 
: the anterior i 
21 
Length, 0.55 5 feaiet SoS from the beak to the pos- 
‘terior part 0 as ventral eee S .71; length of cardinal bor- 
“shett | ay ene, ice sikbiias 3 from the beaks toe 
Be oor or e ny, flattened n , le posterior 
ane ; ornamented with large © habnad. bra 
