350 PROCEEDINGS OP THE ACADEMY OF 







PRISTOSCELTS Lee. 



Under this name I have grouped the species of North America, in which 

 the anterior tibiae are furnished with a distinct series of spines on the outer 

 margin. Important differences in pubescence and form exist among the spe- 

 cies, which have, so far as they were known to him, been distributed by 

 Motschulsky into genera, which he has named Byturosomus (Group I.), Tri- 

 chochrous (Group II.), and Emmenotarsus (Group III.) In order to avoid a 

 change of gender in the specific names of the species thus far described, I 

 have arbitrarily made the generic name masculine, instead of feminine, as 

 required by a strict adherence to classical construction. 



The following table expresses the relations between the species before me : 



I. Prothorax twice as wide as the head, pubescence 



prostrate, with a few intermixed longer 



erect hairs 1. f u s c u s. 



Prothorax scarcely one-half wider than the head : 



II. Pubescence prostrate without intermixed erect hairs : 



Legs entirely black : 



Sides of thorax broadly rounded : 



Pubescence fine 2. ater. 



Pubescence dense 3. oregonensis. 



Sides of thorax strongly rounded 4. laticollis. 



Legs brown or testaceous : 



Thorax quadrate, sides feebly rounded : antenna- black ; 



Pubescence fine, femora darker 5. fulvitarsis. 



Pubescence coarse, femora and tibiae uniform 



in color 6. a t r i c o r n i s. 



Thorax narrowed in front, not transverse; legs rufous : 



Elytra nearly uniform in color 7. convergens. 



Elytra broadly margined with rufous 8. umbratus. 



Thorax transverse, narrowed in front 9. antennatus. 



Thorax transverse, sides strongly rounded; 



Elytra coarsely punctured 10. brevicornis. 



Elytra finely punctured 11. erythropus. 



III. Pubescence intermixed with erect hairs : 

 a. hides of thorax not distinctly serrate : 



Body above densely clothed with coarse brown hair: 



Pubescence short, antennas and feet black 12. b r e vip i lo sus. 



Pubescence long, antennas and feet rufous 13. hirtellus. 



Pubescence long, antennae and feet black 14. sordidus. 



Body above with fine gray pubescence: 



Antennas and legs black, body black : 



Thorax narrowed in front, sides feebly rounded... 15. suturalis. 



Thorax not narrowed in front : 



Sides feebly rounded, and 



distinctly sinuate behind.. 16. q u ad r i col 1 i 8. 



not sinuate behind, hind angles distinct... 17. T e j o n i cu s. 



Sides moderately rounded, hind angles indistinct : 



Head moderate : 



Elytra moderately punctured. 



T ,, i f 18. conformis. 



Legs black < , , . , 



6 (19. squalidus. 



Tibia? and tarsi pale 20. cruralis. 



Elytra very coarsely punctured : 



Thorax transverse 21. aenescens. 



Thorax not wider than long 22. p u n c tipennig. 



Head very large, not narrower than the 



thorax 23. grandicepe. 



[Dee. 



