NORTH aime:rican coleoptera. 217 



II very few specimens. In carinata, for instance, the impression is 

 usually deep and ends very abruptly, but specimens occur with the 

 line as entire as in chahjbea. One of our species has the line termi- 

 nating in a fovea at each end. Color has scarcely any value in the 

 separation of species and can only be used in the most general way 

 as in ignlta the color runs from bright golden to deep blue. 



The sexual character's afford useful means for separating a ceitain 

 number of very closely allied species of rather slender form placed 

 at the end of the genus. 



Among the species included in Haltica are two — nana and Bur- 

 gessi — which form the genus Micraltica of the Class. Col. N. A. 1883, 

 p. 352. This genus made part of the group Crepidoderse, but as 

 both of the species have open anterior coxal cavities they cannot 

 remain in that group, and no course remains but to place them in 

 Haltica, whei'e Crotch placed one of them. 



The genus is a difficult one, and the species can never be deter- 

 mined with any degree of certainty without a fair number of speci- 

 mens, some of which must be males. Unfortunately, this sex is 

 much less abundant than the females. 



To assist students in the determination of species the following 

 table has been prepai-ed, but it must never be relied upon to the ex- 

 clusion of the descriptions, or at least the tabular determination 

 must be verified by reference to the description : 



Body above blue, bronze, green, or cupreous, more or less metallic (head and tho- 

 rax reddish yellow in two species) 2. 



Body above reddish yellow, broadly oval 1.3. 



2.— Elytra lon.gitudinally plicate at the sides 1. biiiiarginata. 



Elytra not plicate 3. 



3. — Antennie and legs in great part yellow, in striking contrast with the color 



of the upper surface 12. 



, Antennae and legs piceous, more or less metallic 4. 



4. — Thorax with a deep ante-basal groove which extends cvmpletely across the 



thorax 5. 



Thorax with a moderate, sometimes obsolete ante-basal groove which is 



never entire 6. 



,5. — Large species i5.5 mm.), usually l)lue, form robust, thorax very distinctly 



wider at base. 2. clialybea. 



Smaller species (2 — 3 mm.), of more elongate form, thorax scarcely wider 

 at base. 

 Surface metallic blue, humeri scarcely evident, elytra rather coarsely and 



closely punctate ; legs brown : species quite small 3. iiaiia. 



Surface distinctly metallic, brassy, green, blue or bronze, elytral punctua- 

 tion distinct 4. igiiita. 



TKANS. AM. ENT. SOC. XVI 1 28) JUNE, 1889. 



