NORTH AMERICAN COLEOPTERA. 71 



pale. Body beueath, except the pro- and mesosteriium, piceous. Legs pale, 

 tarsi slightly darker. Length .20 — .28 inch. ; 5 — 7 mm. 



Male. — Last ventral broadly and moderately deeply emarginate: claws nar- 

 rowly bifid at tip, the parts nearly equal. 



Female. — Last ventral broadly semicircular, usually entire, rarely with a feeble 

 trace of a notch at middle; claws more deeply and widely bifid, the inner por- 

 tion distinctly shorter. 



This species is the smallest in our fauna. The elytral markings 

 seem to vary very little. The sculpture of the elytra is rather 

 coarse, resembling in this respect vmjata and flavolimbata. 



Occurs in Nova Scotia (Ulke), Kansas, Colorado and Wyoming. 



T. atteiiuata Say, Jouru. Acad, iii, p. 459; ed. Lee. ii, p. 223; Lee, Proc. 

 Acad. 1865, p. 220. — Oblong, slightly broader behind. Antennae piceous, gradu- 

 ally paler to base, fifth joint longer than the third. Head yellow, occiput with 

 large piceous transverse space, surface moderately closely punctate. Thorax 

 fully twice as wide as long, slightly narrowed in front, sides subangulate, disc 

 sparsely, obsoletely punctate, a moderately deep oblique impression each side, 

 color dull yellow, with the usual three piceous spots; scutellum piceous, or 

 partly pale; elytra densely and finely punctured, finely pubescent, color in great 

 part metallic-blue or green, the side margin and apex yellow, a discal yellow 

 vitta extends from base a little beyond the middle, broad at base, gradually at- 

 tenuate at apex, or sometimes bifid; epipleurse pale. Body beneath pale, the 

 sides of metasternum and abdomen piceous with metallic surface lusti'e. Legs 

 yellow. Length .24 — .30 inch.; 6 — 7.5 mm. 



Male. — Last ventral segment feebly emarginate; claws finely bifid at tip. 



J^e)ua/e, — Last ventral broadly semicircular, with a very slight notch at middle ; 

 claws bifid behind the apex, the inner portion shorter. 



This species varies in the extent of the dorsal yellow vitta, which 

 extends sometimes two-thirds to aj)ex, or is a short spot at base, the 

 usual extent being to the middle. 



The elytral punctuation is dense and fine, as in canadensis or lu- 

 teodncta. This removes it from suspicion of being a variety of either 

 convergens or flavolimbata, both of which have the coarse sculpture 

 of virgata. T. didacta has still finer sculpture and a small occipital 

 spot. 



Occurs in Kansas, Utah, Nevada and British Columbia. 



T. liiteociucta Lee, Proc. Acad. 1858, p. 88; Proc. Acad. 1865, p. 220.— 

 Form oblong, usually nearly parallel, color variable: green, blue, purple, or 

 purple-black. Anteunse piceous externally, gradually paler to base, fifth joint 

 longer than the third. Head testaceous, with a large occipital space piceous, 

 with more or less metallic surface lustre, sparsely punctate. Thorax not twice 

 as wide as long, sides strongly arcuate, hind angles slightly reflexed, disc sparsely 

 finely punctate, an oblique or oval depression each side, the three spots well 

 marked; scutellum nearly always piceous, rarely partly pale; elytra oblong, 

 nearly parallel, disc variable in color, margin and apex pale, surface densely 



TRANS. AM. ENT. SOC. XX. APRIL, 1893. 



