LECONTE— SYNOPSIS OF PTEROSTICHUS. 241 



scutellar stria is punctiform or completely wanting; the exterior stria? of the elytra 

 are obsolete. The thorax is trapezoidal, narrowed behind, with the posterior angles 

 very obtuse and rounded ; the lateral margin is narrower, the basal impressions 

 short, deep, single ; the parapleurse are short, the sides of tiie abdomen strongly 

 punctured, the last ventral segment simple in both sexes. The mentum tooth is 

 short; the outer margin of the tarsi not grooved. 



20. P. obscurus, nitidus, tliorace latitudine vix breviore postice angustato, angulis posticis rotundatis, 

 basi utrinque profunde breviter impresso, elytris non latioribus, striis 4 profundis, 5'^ tenui, tripunctatis, 

 puncto 2""^° ad striam tertiam slto, pedibus piceis. Long. 42. 

 Feronia obscura Say, Trans. Am. Phil. Soc. 4, 435. Lee. An. Lye. 4, 453. 

 Southern and Western States, very rare. 



2L P. ventralis, nitidus, thoraee subrotundato, angulis posticis fere obsoletis, basi utrinque profunde 

 breviter impresso, elytris striis profundis punctatis, 7""^ antice obsoleta, tripunctatis, puncto 2°'^° ad 

 striam 3""" sito, antennis pedibusque ferrugineis. Long. -35. 

 Feronia ventralis Say, Tr. Am. Phil. Soc. 2, 4G. 



A unique specimen, from Louisiana, kindly given me by Dr. Schaum. 



We have here a numerous division, with three dorsal punctures, and long para- 

 pleurse ; they are usually winged, the thorax is very finely margined, but little 

 narrowed behind, not sinuate, or scarcely sinuate on the sides, with the posterior 

 angles not rounded and scarcely prominent ; the anterior transverse line is interrupted: 

 the basal impressions are single, linear, deep, usually punctured ; the lateral groove 

 on the external margin of the tarsi, which is obsolete in most of the preceding groups, 

 here becomes very deep ; the body is usually flattened, rarely subcylindrical ; it cor 

 responds in part to Dysidius Chaud. 



22. P. lustrans, depressus, thoraee breviusculo, postice subangustato, lateribus late rotundatis, postice 

 subsinuatis, basi punctato, utrinque striato, angulis posticis subacutis, elytris striis impunctatis, interstitiis 

 subeonvexis, 3'° tripunctato. Long. -42. 



LeConte An. Lye. 5, 57. 



San Francisco and San Jose, California. Differs from P. mutus by the thorax 

 being less narrowed behind, and the striae of the elytra finer and without any 

 appearance of punctures. The parapleurse are less punctured, and the base of the 

 abdomen nearly smooth ; the posterior tibiae of the male are slightly pubescent 

 internally. 



23. P. mutus, subdepressus, piceoniger nitidus, thoraee latitudine fere longiore, postice subangustato, 



lateribus rotundatis, basi subrotundato, utrinque punctato et profunde striato, angulis posticis distinctis, 



elytris tripunctatis, striis profundis, punctulatis. Long. 4 — -47. 

 LeConte, Agass. Lake Superior, 206. 

 Feronia muta Say, Trans. Am. Phil. Soc. 2, 44. 



61 



