124 Memoirs on the Coleoptera 



elongate, the elytra ( 9 ) not over one-half longer than wide. 

 Length (cf 9) 8.0-8.8 mm.; width 3. 1-3. 7 mm, Colorado 

 (Boulder Co.), New Mexico and northern Mexico. 



amplior n. subsp. 

 B — Almost similar to placidum but smaller and rather less elongate, 

 blue-black, the female elytra densely opaque; general characters 

 as in placidum, the pronotal foveae less deeply concave, with 

 rather flatter floor and densely punctulate or minutely rugose; 

 elytra nearly similar in outline, striation and dorsal punctures; 

 anterior male tarsi distinctly dilated. Length {<^ 9 ) l-2rl-l 

 mm.; width 3.0-3.2 mm. Mexico (Amecameca). Three ex- 

 amples *aztecanum n. subsp. 



C — Similar to placidum but narrower and relatively more elongate, 

 with broader head and rather larger eyes; antennae similar and 

 with the third joint evidently longer than the fourth; prothorax 

 nearly similar but not quite so abbreviated; elytra narrower, 

 oval, about two-fifths wider than the prothorax, of a more brown- 

 ish black than in placidum; striae smooth, extremely fine, the 

 intervals perfectly flat, the four dorsal punctures very fine, the 

 two anterior at the third, the others at the second, stria. Length 

 {(^) 7.8 mm.; width 2.75 mm. New Hampshire. 



citattun n. subsp. 



Dorsal punctures three in number and less minute 2 



2 — Form oblong, rather more convex, highly polished throughout, deep 

 black, the thoracic reflexed margins feebly diaphanous; legs and 

 tarsi deep black; elytra not in the least less polished in the female; 

 head rather small, slightly more than half as wide as the prothorax, 

 elongate, with well developed and very prominent eyes; impressions 

 as in placidum; antennae very slender, more than half as long as 

 the body, black, the basal joint piceous, the third and fourth equal; 

 prothorax exactly as in placidum in outline and in the strongly 

 reflexed margins, the basal angles more definite though obtuse; 

 base, apex and general surface similar, except that the large and 

 deeply concave foveae are nearly smooth and rather more traceable 

 anteriorly; elytra three-fifths longer than wide, one-half wider than 

 the prothorax, gradually rounded behind, the sinus long and evi- 

 dent; sides somewhat rapidly rounded at base; striae very fine, 

 scarcely diff'erent at apex and with very minute and close-set 

 punctulation throughout; intervals flat or nearly so, the anterior 

 puncture near the third, the two posterior near the second, stria; 

 met-episterna twice as long as wide; tarsi very slender, with coarse 

 deep sulci. Length (9) 7.7-8.7 mm.; width 2.8-3.3 ^n"^- ^'^' 



bama (Salco and Mt. Vernon), — Loding collare Say 



Form less stout, moderately convex, bright metallic green throughout 

 above, shining, the elytra somewhat less so; under surface and 

 epipleura greenish-black; legs dark rufous, the tarsi blackish; head 

 moderately elongate, much narrower than the prothorax, with well 

 developed and prominent eyes, the impressions deep and parallel 

 but irregular; palpi blackish; antennae black, with piceous basal 

 joint, slender, fully half as long as the body, the third and fourth 



