345 



circular, punctured depression, with elevated centre. Striae of the elytra 

 impunctured, basal dilated interstitial puncture wanting. Tarsi pale 

 reddish brown. 



0. *suhpunctaius. Black, glabrous; thorax broadest before the middle, 

 and gradually narrowed to the base; striae obsoletely punctured. 



Length over half an inch. 



Body glabrous, black. Antenna3 entirely black except the tip of the 

 terminal joint which is ferruginous. Palpi black. Thorax broadest consid- 

 erably before the middle, behind which the lateral margin is nearly straight 

 to the posterior angles, which are very slightly excurved and acute; poste- 

 rior margin narrower than the anterior; base with the double lateral striae 

 distinct but short, and vanishing in a rugose punctured dejiression. Elytral 

 striae obsoletely punctured. Pectus and postpectus punctured at the sides. 

 Feet black, tarsi tinged with piceous beneath. 



O. *politus. Black, polished; anterior and posterior thoracic margins 

 nearly equal, posterior angles excurved, basal indentations elongated, 

 sparsely punctured. 



Length over nine twentieths of an inch. 



Body deep black, highly polished. Three basal joints of the antennae 

 black, polished, remaining ones fawn-colored and downy terminal joint pale 

 ferruginous at tip. Palpi fawn-colored. Thorax broadest nearly in the 

 middle; anterior and posterior margins almost equal, lateral margins regu- 

 lai'ly curved, at the base slightly excurved; posterior angles not prominent; 

 basal lateral impression deep, with a few remote punctures, internal longi- 

 tudinal stria elongated, dilated at base, external one obsolete. Elyti-ti with 

 minutely punctured striae. Pectus and postpectus punctured, the former 

 inconspicuously. Tibi;e and tarsi pale piceous above, fawn-colored beneath. 



0. *hamaius. Black, polished; basal thoracic lateral lines unituig into a 

 hook; tibiae and tarsi fawn-colored. 



Length nearly two fifths of an inch. 



Body highly polished, black with violaceous reflections. Three basal 

 joints of the antennas castaneous, polished, remaining ones fliwn-colored, 

 terminal joint at tip ferruginous. Palpi reddish brown. Thorax of similar 

 proportions and shape as in 0. politus ; lateral indentations of the base 

 rough with confluent punctures, each with two impressed lines, the internal 

 one longest, curving outward ne^ the posterior margin, and uniting with 

 the very short external line so as to form a hook. Elytral strias minutely 

 punctured. Pectus and postpectus punctured. Legs pale piceous, tibiaa 

 and tarsi pale reddish brown or fawn-coloreci. 



Subgenus Calathus. 

 In addition to the characters of the genus as given by Latreille and 



