BEETLES OF THE GENUS MYOCHROUS — BLAKE 19 



is also considerable resemblance to the southern Mexican species, 

 M. carinatus Jacoby, but the thorax is more convex and has denser, 

 more confluent punctures than does that species. 



MYOCHROUS MELANCHOLICUS Jacoby 

 Plate 1, Figure 4 



Myochrous melanchoUcus Jacoby, Biologia Centrali-Americana, Coleoptera, voL 



6, pt. 1, p. 174, 1882. 

 Myochrous carinatus Jacoby, in Bryant, Ann. Mag. Nat. Hist., ser. 9, vol. 12, p. 137, 



in part, 1923. 



About 5 mm. in length, elongate oblong, rather flat, shining black 

 beneath the pale closely appressed scales, scales on head unusually 

 fine, showing punctation beneath ; punctation on thorax not confluent 

 or ridged, the punctures separate and not very coarse; thorax only a 

 little wider than long. 



Head compared with other species rather bald, the scales unusually 

 fine over the occiput, a bit coarser behind the eyes; the sculpture 

 plainly visible, consisting of rugose, irregular punctures and the 

 usual ridges on either side of the occiput. Antennae of the usual 

 proportions. Prothorax a very little wider than long with a 3-toothed 

 margin, not very convex, a faint depression on either side below the 

 middle and a well-marked depression along the base, especially over 

 the scutellum ; punctures not so dense or coarse as in carinatus and not 

 in lines, denser and larger toward the base; scales not very thick. 

 Elytra only slightly convex, without basal callosities, a faint trans- 

 verse depression in basal half in which there is a tendency to trans- 

 verse ridging; punctures well spaced, not very coarse except about 

 scutellum; scales easily rubbed off but apparently not dense, rather 

 coarse and pale. Body beneath having the first abdominal segment 

 with small scattered punctures. Hind femora blimtly toothed, ante- 

 rior tibiae with the usual inner tooth. Length 5.2 mm. ; width 2.3 mm. 



Cotype. — In Bowditch collection. Museum of Comparative Zoology ; 

 ? cotypes in British Museum of Natural History. 



Ty'pe locality. — In an endeavor to exclude other species that may 

 be included in Jacoby's material, I hereby designate Cordoba, Mexico, 

 Salle collection, as the type locality. 



Remarks. — There was some confusion in Jacoby's understanding of 

 Myochrous melanchoUcus. In his original description he gives the 

 following localities: Cordoba, Texpam (Salle), Play a Vicente 

 (Hoge), Panama (coll. Jacoby). In the Supplement (1891) he adds 

 Villa Lerdo in Durango, Cholula in Puebla, and Frontera in Tabasco 

 (Hoge) . In the Bowditch collection at Cambridge are further speci- 

 mens from Jacoby's collection containing two additional localities — 

 Paso del Norte, Chihuahua, and Acapulco, Mexico. Of Jacoby's 

 specimens mentioned in the Biologia I have examined specimens from 



