Horn.] 4zXO [Sep. 19, 



Elytral intervals, either flat or alternately elevated, in their 

 entire length; striae moderately tinely punctured. 

 Thoracic smooth lines unequal among themselves, and of 

 varying width, sometimes obliterated. 

 Elytral intervals more or less convex, always alternating, 



striae moderately deep pertinax. 



Elytral intervals flat, equal, stride fine robustus. 



Thoracic smooth lines equal, parallel entire, strongly ele- 

 vated. 



Elytral intervals alternately sub-costiform costipennis. 



Third interval strongly elevated at basal half, striae coarsely 

 punctate. 

 Rostrum normal at tip, median thoracic smooth space dila- 

 ted in rhomboid at middle cariosus. 



Rostrum suddenly dilated at tip and obliquely truncate, 



median thoracic line entire and not dilated latinasus. 



S. pertinax Oliv. V., 83, p. 90, pi. 28, fig. 417; Gyll. Schonh. Gen. 

 Cure. IV., p. MS ; Say. Am. Ent. edit. Lee. I., p. 288 ; interstitialis, 

 truncatus Say. loc. cit ; ? canaliculatus Boh. Sch. Gen. Cure. VIII. 2, 

 p. 25:J. 



This species is extremely variable in form and sculpture, but does not 

 admit of further division than merely into varieties, which pass from one 

 to another through every conceivable grade. The following is the 

 description of the typical form. 



Black, moderately shining beneath, sub-opaque above. Rostrum three- 

 fourths the length of thorax, moderately compressed, scarcely broader at 

 tip, surface very minutely, at base more evidently punctulate and above 

 at base, with a slight channel, slightly broader and deeper posteriorly. 

 Thorax longer than wide, apex constricted, base feebly bisinuate, sides 

 strongly arcuate in front, sub-parallel at basal half ; surface with three 

 entire elevated smooth lines, the middle nearly entire, beginning at apex 

 in a moderately fine line, rapidly widening ; at a point in front of middle 

 suddenly narrowed, and from thence to apex continued by a line broadest 

 in front, gradually narrowing to base, and at tip confused by the basal 

 punctures ; lateral vittae entire, beginning at the apical constriction and 

 ending at the basal margin, inner edge sinuous opposite the dilatation of 

 the median vitta, at which point a lateral branch is given off, usually 

 slender and attaining the basal angle, the portion of the lateral vitta 

 posterior to this branch is always broader ; space between the vitta? and 

 to the sides, coarsely punctured and more or less filled with luteous 

 coating. Scutellum not sulcate. Elytra at base conjointly feebly emar- 

 ginate, broader at humeri and arcuately narrower towards apex, which 

 is feebly rounded or subtmncate, surface striate, strne inconspicuously 

 punctate, intervals feebly alternating in width and convexity, the broader 

 and more convex denuded, the others with luteous coating, surface 

 (when denuded) very minutely punctulate. Pygidium sparsely and 



