Horn.] 



326 



[June CO, 



Dorsal striae not hooked at base ; thorax 

 very minutely punctulate. 

 Sutural stria not joining- an apical line, 



the latter obliterated at middle convexiusculus. 



Sutural stria continued by an entire api- 

 cal line minutus. 



Fourth dorsal arched at base, sutural inter- 

 rupted at base. 

 Sutural stria moderately deeply impressed, 

 abbreviated at base only. 

 Color piceous ; pygidium smooth at apex. scissus. 

 Color, brownish; pygidium sparsely punc- 

 tured scrupularis. 



Sutural stria very feeble, interrupted at base 



and apex wacoensis. 



Elytra more or less punctured over the entire sur- 

 face ; thorax either densely punctured over the 

 entire surface or punctured as strongly at mid- 

 dle as at the sides. 

 Fourth dorsal joining the sutural by a strong 

 arc ; pygidium moderately convex. 

 Sutural stria feeble at base ; thorax sparsely 



punctured laridus. 



Sutural stria strongly impressed ; thorax rather 



densely punctured insertus. 



Fourth dorsal simply hooked at base ; pygidium 

 strongly convex, apical portion indexed at a 



right angle to the superior portion .• . sequipunctatus. 



Thorax ciliate at the sides ; head coarsely punc- 

 tured ; sutural stria interrupted at base ciliatus. 



From the construction of the above table it will be iuferred that the 

 species are very closely allied, and it is probable that collections made 

 across the continent will unite some of those, not only in this but also 

 in other groups, which are separated on trifliug characters, which are 

 really more geographical than entomological. I have united three 

 species under the name insertus, to avoid the other alternative of giving 

 nearly every specimen a name. 



S. aeneicollis, Mars. Mon., 1855, p. 424, pi. 17, fig. 56 ; Horn, Trans. 

 Am. Ent. Soc, 1ST0, p. 141. 



Form moderately robust, surface metallic, thorax dark, elytra greenish- 

 blue. Head moderately densely punctured, front slightly impressed, 

 without stria. Thorax impressed at the anterior angles, disc smooth, at 

 sides coarsely punctured, punctures more dense in front, margin com- 

 paratively smooth. External subhumeral stria short but distinct, hume- 

 ral oblique moderately impressed, internal subhumeral deeply impressed, 

 apical, not joining the humeral ; first dorsal long, extending three- 



