14 PROCEEDINGS OF THE NATIONAL MUSEUM vol. loi 



25. Prothorax with anterior margin projecting over liead, surface 



densely but not coarsely punctate (Bolivia) mamorensis, new species 



Prothorax with anterior margin not projecting over head, coarsely 

 but not very densely punctate (Amazon Valley, Brazil) . 



brunneus, new species 



26. Thorax densely and coarsely punctate (Paraguay) normalis, new species 



Thorax not very densely punctate (Barbados, Grenada, Trinidad, 



British and Dutch Guiana) barbadensis Blake 



M. -figueToae Brethes is not included in this key, since no male 

 specimens have been available. The beetle resembles M. armatus Baly 

 but has not so large a thorax. 



MYOCHROUS DENTICOLLIS (Say) 



PLATE 1, Figure 1 



Colaspis denticollis Say, Journ. Acad. Nat. Sci. Philadelphia, vol. 3, p. 448, 1824. 

 Myodirous denticollis LeConte, Writings of Thomas Say, vol. 2, p. 215, 1859. 



From 4 to 5.5 mm. in length, broadly oblong, black with a bronzy 

 luster, moderately lightly covered by narrow brownish and white 

 scales. Prothorax broadly rounded and without marked convexities, 

 with a little depression over the scutellum and a 3-toothed margin; 

 surface with fine lines of dense, confluent, and shallow punctures; 

 elytra with coarse, dense, and, in basal half, contingent punctures in 

 rows visible through the scales. 



Head down to antennal sockets covered by scales completely hiding 

 the punctation, a narrow ridge extending down on each side of oc- 

 ciput, the punctation beneath the scales in fine lines radiating from 

 a shallow median vertical depression ; lower front between the anten- 

 nal sockets shining under the light, white pubescence, the scales here 

 becoming less dense and more hairlike, each one coming from a coarse 

 puncture ; punctures here not quite so dense and producing a wrinkled 

 effect across lower front. Antennae not extending much below humeri, 

 a little shorter in the female, reddish brown, joint 1 broadly cylin- 

 drical, joint 2 globular, joints 3 to 6 slender, shining, 7 to 11 

 thicker and densely pubescent. Prothorax considerably broader than 

 long, broadly rounded but not very convex, with a little depression at 

 base over the scutellum, sides with three teeth and a tooth at apical 

 and basal angles; punctation visible through the scales, dense and 

 confluent, in fine, shallow, longitudinal lines. Elytra only a little 

 wider than prothorax, moderately convex, humeri prominent with 

 short intrahumeral depression, the rows of punctures close in the 

 basal half, but the punctures becoming finer and less dense toward 

 the apex; scales not so dense as to hide the punctation, narrow and 

 somewhat curved, not lying flat, the scales from the middle of the 

 punctures narrower and smaller and lying more appressed to the sur- 

 face. Body beneath shiny, not so densely scaly, coarsely punctate 



