1S64.] 



35 



clypeus, mandibles and antennae as in the preceding species. Thorax 

 densely and finely punctured, brilliant green with blue reflections, 

 clothed with rather long black pubescence; scutellum and metathorax 

 bright green, the latter deeply impressed on the disk ; tegulfe black, 

 smooth and polished. Wings subhyaline. apical margins faintly clouded ; 

 nervures blackish. Legs green, clothed with short black pubescence. 

 Abdomen elongate, subovate, densely and minutely punctured, brilliant 

 green, changing to deep blue in certain lights, clothed towards the 

 apex with very short black pubescence ; basal segment in front deeply 

 impressed ; beneath, the ventral scopa is dense and black. Length 

 4i lines. 



Hah. — Rocky Mountains, Colorado Territory. One specimen. Coll. 

 Entom. 8oc. Philadelphia. 



Closely resembles 0. fulgida in color and punctation, but the form 

 is more linear and not so robust ; the abdomen is subovate and not sub- 

 clavate as in that species. The color in both species is very bright 

 and beautiful. 



28. 0. pusilla, n. sp. 



Male. — Head dark blue-gi'een, finely and densely punctured, clothed 

 with pale hairs ; anterior margin of the clypeus uneven ; antennae not 

 as Ions: as the thorax, black, fluirellum testaceous beneath. Thorax 

 dark blue-green, densely and finely punctured, clothed with long pale 

 hairs ; tegulae green, smooth and shining. Wings hyaline, the apical 

 margins very faintly clouded ; nervures blackish. Legs blue-green, 

 sparsely clothed with short pale pubescence. Abdomen elongate, subo- 

 viite. dark blue, slightly tinged with green ; shining, densely and mi- 

 nutely punctured, the apical margins of the segments smooth ; the seg- 

 ments above clothed with whitish pubescence, that on the sides of the 

 basal, and on the apical segments longer and more dense ; apical mar- 

 gin of the sixth segment somewhat reflexed and deeply notched in the 

 middle; apical segment bidentate; beneath, the ventral segments are 

 flat, deep blue and pubescent. Length 3i lines. 



Hah.—V^Qs Peak. Col. Ter. One specimen. Coll. Ent. Soc. Philad. 



29. 0. pumila, n. sj). 



Female. — Head as wide as the thorax, deep blue, densely and finely 

 punctured, clotbed with rather long whitish pubescence; anterior mar- 

 gin of the clypeus truncate ; mandibles stout, black, apical tooth long 



