44 PROCEEDINGS OF THE NATIONAIi MUSEUM vol. loi 



MYOCHROUS CHACOENSIS, new species 



Plate 4, Figure 7 



Approximately 7 mm, in length, broadly oblong oval, shining black, 

 covered by pale vrhite and brown scales forming on the elytra a 

 semivittate pattern; thorax almost as long as broad, projecting over 

 head with a thickened anterior -margin ; strongly convex with a 3- 

 toothed lateral margin; surface rather finely and not very densely 

 punctate; elytra with well-spaced punctation. 



Head somewhat receding with a median vertical groove down front 

 and a well-developed ridge on either side of occiput; the punctation 

 covered by dense, closely appressed scales. Antennae pale, of the 

 usual proportions. Prothorax almost as long as broad with the an- 

 terior margin thickened and also concealing the head, with a slight 

 median impression over the occiput ; strongly convex, depressed along 

 the basal margin ; sides 3-toothed ; surface finely and not very densely 

 punctate. Elytra twice as long as thorax, strongly convex with 

 prominent humeri and at base two short costae, otherwise depressed 

 along the basal margin; a slight transverse depression below the 

 humeri; striate punctation not very coarse or dense and covered by 

 the broad, closely appressed pale brown and white scales, the scales 

 forming indistinct brown and white vittae. Body beneath shining 

 black with fine white scales, the abdomen without scales down the 

 middle, first segment finely and not very densely punctate. Tibiae 

 reddish brown, anterior ones with a distinct tooth on inner side and 

 another at apex. Length 6.9 mm. ; width 3.3 mm. 



Type. — A female in Miguel Lillo Institute, Tucuman, Argentina, 

 collected by F. Monros. 



Type locality. — Eesistencia, Chaco Province, Argentina. 



Remarks. — As in the case of M. stenomorphiis and M. ^/nonrosi, as 

 well as of M. spinipes and 31. mamorensis, this species, although sepa- 

 rated by a thousand miles, has a close relative, M. holimanus. In all 

 three the closely related species resemble each other strongly but have 

 minor differences. In this case, M. chacoensis is a bit larger and 

 darker, with paler scales having a different color pattern on the lower 

 surface as well as above. 



MYOCHROUS CURCULIONOIDES Lefevre 



Plate 5, Figure 5 



Myochrous curculionoides Lefevre, Ann. Soc. Ent. France, ser. 6, vol. 9, p. 21, 

 1899.— Jacoby, Entomologist, vol. 30, p. 263, 1897. 



About 6 mm. in length, thorax much narrower than elytra, which 

 are broadly oblong; deep reddish brown to piceous black, covered 

 with broad yellowish scales, surface beneath coarsely and densely 

 punctate, thorax strongly convex with two gibbosities on anterior 

 margin and deeply sulcate between; sides with two, possibly more, 



