Neithea whitneyi

This species has a shell that generally measures 1cm x 7mm x 4.5mm.  The shell is small and subtrigonal, and it is also higher than long and almost equilateral.  The postero-dorsal margin is slightly shorter than antero-dorsal margin.  The anterior ear is large and prominent, pointed, transversely rounded, and the posterior ear is rudimentary, triangular, and pointed.  The ventral margin is convex and sinuous.  The right valve is convex and the left is more or less flat.  This species is similar to Neithea wrighti, which is more nearly equilateral, narrower, and more convex.  The ribs of the Neithea whitneyi are more prominent than those of Neithea wrighti, having steep sides, whereas those of  Neithea wrighti have more sloping sides.  This form is relatively rare in the Buda Limestone, but it was found in the lower division of the Buda Limestone, Austin, and Manchaca, Texas.