Size: 3.8-4.2

Seasonality: April-October

Distribution; Western USA and Canada

Information: may be found running erratically across.among stony substrates, gravel, and sandy soils mostly along rivers and streams. May be found on almost every islet found along the Willamette River. May be found during the day on patches of sandy mud along rivers, moving on top of and under stones on river banks, and resting under stones and debris along the water. 

Description: body: elongate-quadrate, robust. Body, dorsal and ventral faces, glossy silvery-grey. Head fairly large compared to pronotum size; wide, triangular.  Head smooth, slight wrinkles around the eyes; eyes fairly small, close to head. Antennae black, antennal pubescence begins on the first antennomere after the pedicel. Pronotum fairly small, cordate-triangular, hind angles pointed, curved to point away from the pronotum laterally. Front pronotal angles acute, but margins do not curve towards head. Pronotal lateral margins thin, not well-defined, but slightly upturned. Median line deep. Abdominal/elytral regions elongate-truncate. 8-9 striae per elytron, intervals elevated into minor costae. Elytral apices truncate, tip of abdomen protruding barely from underneath elytra. Humeral angeles squared, rounded off. Ventral faces glossy black, legs glossy black. Body relatively flat.