DICAELUS. Bon. 



This genus contains a number of large species, usually pure black, 

 but some of them are of a beautiful violet or bronzed purple; found only 

 East of the Rock}- Mountains under stones or pieces of wood. 



We owe the following table to the kindness of Geo. H. Horn, M.D. 



Thorax distinctly narrower at apex than at base 2. 



Thorax as wide or wider at apex than at base 12. 



2. Thorax at middle of margin with one sehgerous puncture 3. 



Thorax at middle of margin with two setigerous punctures 11. 



3. Elytra without stride, simply with rows of punctures .... 1, lajvipemiis, Lee. 

 Elytra striate 4. 



4. Intervals not interrupted 5. 



Intervals interrupted by ocellate punctures 10. SClllptilis, Lee. 



5 . Intervals equal 6. 



Intervals alternately broader and more convex 10. 



6. Stride not punctured 7. 



Striae very distinctly punctured 12. crenatUS, Lee. 



7. Large species, transverse basal impression distinct 8. 



Smaller species, disc of thorax nearly flat 13. OVallS, Say. 



8. Form elongate, margin of thorax reflexed posteriorly. ... 15. ambigUUS Ferte. 

 Form broad, margin of thorax not reflexed posteriorly o 



9. Surface black 



Ely tral intervals broad and regularly convex, humeral carina very long 



2. costatus, Lee. 



El. intervals narrow and more suddenly convex, humeral carina 



one third the length of elytra 3, dilatatUS, Say. 



El. intervals moderate, flat; form depressed, carina long 4, planicolllS, Lee. 



Surface cupreous or brassy 5 _ splendidllS, Say. 



Surface purple, form more elongate Q. purpuratllS, Bon. 



10. Intervals feebly alternating, humeral carina moderate ll.furVUS L»ej. 



Intervals very decidedly alternating in width and elevation, carina long. 



The intervals smooth, impunctate 



Humeral carina moderately elevated, acute near the base only 



7. quadratus, Lee. 



Humeral carina very long and more elevated, acute in the entire length 



8. carinatus, Dej. 



The narrower intervals distinctly punctulate, the humeral carina moder- 

 ately elevated 9, altemailS, Dej. 



11. Form moderately elongate, intervals equal, feebly convex, stria sometimes 

 finely punctured, carina moderate \\ t elongatllS Bon. 



12. Thorax decidedly narrower posteriorly; surface scarcely shining, carina 



short Ig. fcetg^ Bon. 



Thorax nearly square, not narrowed behind; surface shining, carina almost 

 entirely^ wanting 17, potftus, Dej. 



BIBLIOGRAPHY. 



1. lavipennis, Lee. Ann. Lye. IV, 321. Col. Utah. — 20mm. 



2. costatus, Lee. Class. Carab. p. 389. Tex. — 22-25 mm. 



3. dilatatus, Say. Trans. Am. Phil. II, 68. Lee. Ann. Lye. IV, jzo. N. Y. Pa. Ohio, 



Mo. Ills. D. C. Va. Md. Tex.— 20-25 mm.- 

 =Dejeami, Dej. Spec. V, 687.= quadratus, Ferte. Ann. Fr. 185 1. p. 277. 

 Bull. Brooklyn Ent. Soc. Oct. 1880. 



