186 MR. MARTIN JACOBY ON NEW SPECIES [Mar. 4, 



I must separate this species from any other on account of the 

 impunctate thorax, which even under the strongest lens shows no 

 trace of any punctuation. Examples of both sexes are before me, 

 and do not seem to vary except in the slightly broader thorax 

 of the female. 



Lacuna semirugosa, sp. n. 



Metallic green, glabrous above, below bluish; thorax sub- 

 quadrate, finely punctured, the transverse sulcus deep; elytra 

 widened below the middle, very closely and strongly punctured, 

 the interstices more or less rugose. 



Length 7 millim. 



Head very finely transversely wrinkled, without punctures, the 

 frontal elevations strongly raised, pyriform, carina acute ; antennse 

 long and slender, metallic blue at the four or five basal joints, 

 the rest black, third and fourth joints equal, shorter than the 

 fifth ; thorax about one-half broader than long, the sides nearly 

 straight, very slightly narrowed anteriorly, the surface very 

 finely but not very closely punctured, the basal sulcus deep and 

 nearly straight, bounded laterally by a deep perpendicular groove ; 

 scutellum blackish; elytra widened below the middle, without 

 basal depression, comparatively strongly and very closely punctured, 

 with finely wrinkled interstices ; below very sparingly pubescent. 



Hah. Colombia. 



I know of no other species of Lactina with such strongly 

 punctured elytra in connection with the glabrous upper surface. 

 The description is that of the male, in which the anterior tarsi 

 are dilated, and the last abdominal segment has a central narrow 

 groove ; the female does not differ except in the more slender 

 tarsi and the generally rather larger size. 



Lactina glabrata, sp. n. 



Metallic dark blue, glabrous above ; thorax one-half broader 

 than long ( c? ), nearly impunctate, with deep sinuate sulcus ; 

 elytra very closely and distinctly punctured. 



Length 6 millim. 



Male. Head impunctate, the frontal tubercles strongly raised, 

 oblique, the carina acute ; the antennae nearly extending to the 

 apex of the elytra, metallic blue, the thu-d joint slightly longer 

 than the fourth and as long as the fifth joint ; thorax one-half 

 broader than long, the sides straight at the base, slightly rounded 

 antei'iorly, the anterior angles thickened, the sm-face with a deep 

 sinuate sulcus, the anterior portion rather convex, very minutely 

 and somewhat closely punctured as well as the base below the 

 sulcus ; scutellum small, impunctate ; elytra convex, not widened 

 posteriorly, attaining their greatest convexity at the middle, very 

 closely and rather strongly punctured, the apex of each rounded, 

 their epipleurse concave, impubescent ; below and the legs smooth, 

 shining ; the male organ curved, parallel, the apex luther blunt, 

 with an elongate cavity. 



