BEETLES OF THE GENUS MYOCHROUS — BLAKE 43 



MYOCHROUS BOLIVIANUS, new species 

 Plate 4, Figube 6 



From 5.5 to 6.5 mm. long, broadly oblong, deep reddish brown, 

 prothorax nearly half as long as elytra, with three tiny lateral teeth, 

 and a thickened anterior edge covering occiput, densely covered with 

 short, broad, pale brown and white scales forming a pattern with two 

 to four white spots on elytra ; punctation beneath scales fine, not dense. 



Head somewhat receding, the occiput bulging and with the usual 

 occipital ridges on either side, and in some specimens a well-marked 

 median line down front ending in a depression, often almost a pit, in 

 the middle of the front ; labrum unusually small ; head covered with 

 dense, closely appressed scales down to antennal bases, beneath the 

 scales the punctation rather fine and moderately dense. Antennae 

 reddish brown, of the usual proportions. Prothorax large, almost as 

 wide as elytra, and a little wider than long, convex, with a peculiar 

 thickening along the anterior margin over the head, almost concealing 

 the occiput from above, and a depression behind this; the lateral edge 

 with three small teeth and a small apical and basal tooth ; surface shin- 

 ing reddish brown or piceous with moderately fine, well-spaced punc- 

 tures ; a row along basal margin forming a depressed line ; scales very 

 dense, often forming a pattern with a white median line extending 

 halfway down thorax and a broad white area on each side, this pattern, 

 however, variable. Elytra rather convex, especially in the middle, 

 with sharp humeral prominences and intrahumeral depression extend- 

 ing down below a slight basal callosity; surface very shining, deep 

 reddish brown or piceous with rather small striate punctures becoming 

 fine toward the apex. Scales forming a pattern in some specimens, 

 having on each elytron a white spot before and after the middle and 

 smaller lateral spots, these, however, variable. Body beneath fairly 

 densely covered with somew^hat thinner scales, covering the puncta- 

 tion ; unusually long hairs between the anterior coxae. A blunt tooth 

 on posterior femora, and a tooth also on inner side of anterior tibiae. 

 Length 5.5 to 6.5 mm. ; width 2.6 to 3 mm. 



Type and paratypes. — Type male and seven paratypes, U.S.JN.M. 

 No. 59017, collected October 23 to November 9, 1921, by W. M. Mann, 

 Mulford Biological Expedition. 



Type locality. — ^Rosario, Lake Rogagua, Bolivia. 



Other localities. — San Gregorio, Bolivia (W. M. Mann, October 

 1921). 



Remarks. — This is an unusually distinctive species, characterized 

 by its short, chunky shape and the markings of the scales. The thick- 

 ened anterior margin of the prothorax is similar to that in the cur- 

 culionoides group. It differs from these species in having a much 

 broader prothorax which is nearly as wide as the elytra. Dr. Mann 

 states that he collected it on the border of the lake. 



