66 PROCEEDINGS OF THE ACADEMY OF 



dorsal vitta ochreous, slightly incurved at the apex ; base of tibiae 

 pale. L. .10. California. 



J* Fifth joint of antenna very large, elongate, quadrate. 



2. 0. Zimmermanni, sp. n. 



Ver}' close to O. lejndula, but the elytral vitta is deepl}^ exca- 

 vate outside, straight at the base and incurved at the apex; base 

 of tibiai pale. L. .10. Missouri (Riley). 



J* Fifth joint of antennae very large, elongate quadrate. 



3. 0. vittata (Fab.), Syst.El., i. p. 469. 



Allied to 0. lepidula but more oval; head smooth; thorax aluta- 

 ceous, punctate ; elj'tral vitta deeply excavate externally, incurved 

 at base and apex ; four anterior legs and base of autennai yellow. 

 L. .9 Atlantic region. 



^ Fifth joint elongate, not dilated. 



4. 0. oregonensis, sp. n. 



Allied to 0. striolata^ by the shape of the elytral vittaj and the 

 red base to the antennoe, differing by the shining thorax, dark 

 legs (base of tibife alone pale). L. .11. Oregon (Horn). 



J* fourth and fifth joints dilated. 



B. Elytra each xvith two pale spots. 



5. 0. bipustulata (Fab.), Syst. El., i. p. 464. 



Ovate, black; base of antennaj and legs entirely pale red; 

 bead and thorax finely and sparingly punctulate; elytra sparsely 

 subseriate-punctate, each with two fulvous spots, one large basal, 

 one subapical. L. .10. Middle States. 



. C. Elytra unicolorous. 



6. 0. albionica (Lee). 



Bronzed, evidently punctate ; antennae with the first joint black, 

 2-4 pale ; thorax transverse, sides rounded ; head punctate, cari- 

 nate between the antennre. L. .8. California, Texas. 



I cannot satisfactorily separate the Texan specimens of this 

 species. 



7. 0. Lewisii, sp. n. 



Very like 0. albionica^ but entirely bluish-green, more evidently 

 punctate; antenna? with the base entirely red. L. .0. Colorado, 

 Illinois. 



