50 PROCEEDINGS OF THE NATIONAXi MUSEUM vol. loi 



la ponctuation comme celle du pronotum, et serriee, les espaces non 

 releves; cependant le premier espace lateral est presque en crete 

 aigue surtout pres du callus. La ponctuation du dessous du corps 

 est bien moins forte qu'en dessus ; une forte impression mediane sous 

 le 5 segment de I'abdomen. Les pattes sont subegales, les cuisses en 

 massue, les tibias anterieurs avec une dent au cote inferieur vers le 

 tiers apical. 



"Un examplaire recueille a La Plata le 12, IV, 1923 par mon eleve, 

 Mr. Robert Figueroa Lopez, qui est une vraie experance pour I'Ento- 

 mologie Argentine." 



Bemarhs. — F. Monros, of the Institute Miguel Lillo at Tucuman, 

 Argentina, has sent me two specimens about which he writes as 

 follows : "One species has been compared with one in Brethes collec- 

 tion in Buenos Aires labeled Myochrous platensis which I believe is 

 that one he later described as M. f.gueroae Brethes, 1925. So this 

 material could be homotypic." Both specimens unfortunately are 

 females. In general appearance they resemble closely M. armatus 

 Baly, but I believe they are not that species. The thorq^x is not so 

 large and is not one-third the length of the beetle as is usual in most 

 specimens of M. armatus. Furthermore, the punctation of the thorax 

 is more ridged toward the base and the punctation of the elytra coarser 

 and with less interspacing, and, except at the base, the rather pro- 

 nounced costae usual in M. armatus are lacking. Both specimens were 

 taken in the delta of the Parana River, in Buenos Aires Province. 



MYOCHROUS SAPUCAYENSIS, new species 



Plate 6, FiGtrRE 2 



About 5,5 mm. in length, elongate oblong, shining black with short 

 pale scales ; thorax nearly as long as wide, not very convex, 3-toothed, 

 very densely and coarsely but not rugosely punctate ; elytra not much 

 wider than thorax. 



Head covered by short, closely appressed brown and white scales 

 to antennal sockets, lower front with very short and indistinct scales 

 or hairs, a median line down occiput and the usual ridge on either 

 side. Antennae deej) reddish brown, of the usual proportions. Pro- 

 thorax not quite so long as wide, and about half as long as the elytra, 

 rather flat, with a transverse depression anteriorly and a slight basal 

 depression most marked in the middle, three well-developed lateral 

 teeth and a small apical and basal tooth, surface very densely and 

 deeply punctate, the punctures round and regular, not rugose or 

 confluent, scales rather short and curved, in this single specimen 

 examined much rubbed and not concealing the punctures. Elytra 

 not much wider than thorax, with little trace of a basal callosity, a 

 slight transverse depression in basal half; punctation coarse, deep, 

 and dense, with a little tendency toward transverse ridging in basal 



