﻿Dec. 1805] WUKHAM. COLEOl'TERA OF N. E. AMERICA. 181 



Pterostichus Bon. 



Antennal grooves wanting beneath, two supra-orbital setae, scrobe 

 of mandible without setigerous puncture. Hind cox?e contiguous, 

 margin of elytra with posterolateral interruption, three basal joints of 

 antennae smooth, head not greatly constricted behind the eyes. Ter- 

 minal joint of labial palpi not dilated and not shorter than the penulti- 

 mate which is bisetose anteriorly. Anterior tarsi of $ transversely di- 

 lated. 



Usually black shining species, sometimes with metallic or purplish 

 luster. Form elongate, more or less depressed. They are common in 

 woods under logs, stones or leaves, while many are to be found in the 

 spring under all kinds of shelter. From its great size the genus is quite 

 difficult to handle. The essentials used in the following table are in 

 the main those suggested by Dr. LeConte, whose papers have been freely 

 used. 



Syfiopsis of Species. 



Dorsal punctures wanting 2 



Dorsal puncture single 5 



Dorsal punctures two or more 11 



2. Head of moderate size 3 



Head greatly enlarged 4 



3. Presternum margined at tip COngestus. 



Prosternum not margined at tiji adoxus. 



4. Hind trochanters acute at tip grandiceps. 



Hind trochanters rounded at tip rostratus. 



5. Basal fovea of prothorax double or bistriate 6 



Basal fovere of thorax single 9 



6. Hind angles rectangular, longer and prominent 7 



Hind angles subobtuse or very small 8 



7. Legs black anterior transverse thoracic line evident substriatus. 



Legs reddish transverse line obsolete or wanting incisus. 



8. Elytral striae punctulate vinctus. 



Elytra! striae smooth apalachius. 



9. Hind angles of thorax rectangular, prominent. Elytral striae deep, small species 



(.32 in.) honestus. 



Hind angles nearly rectangular, large species (.75 in.) unicolor. 



Hind angles rounded or obtuse 10 



10. Larger (.75 in.) Elytral striae very fine rotundatus. 



Smaller (.41 in.) Elytral stria profound, thorax without anterior impressed 



line obsoletus. 



Small (.40 in.) Internal elytral strire deep, thorax with deep anterior impressed 



line near margin approximatus. 



