333 [June, 



slightly compressed, last joint oval, not acuminate. Thorax subcampaniilate, 

 sparsely punctured, shining, broadly impressed before the middle, obsoletely 

 channelled, deeply foveate at the middle of the base. Elytra wider than usual, 

 dilated behind and convex, scabrous, with close set punctures. Beneath green- 

 ish black ; middle tibice slender, scarcely curved ; posterior tibiae with two small 

 equal acute spurs. 



18. L. convex a, minus elongata, nigra, capite thoraceque parce punctatis, 

 convexis, hoc ovali, subcanaliculato, basi medio foveato, elytris cyanescontibus 

 postice dilatdtis, scabro-putictatis, antennis subserratis. Long. -41. 



Mexican Boundary Commission; collected by Mr. Clark, imder Col. J. D. 

 Graham. Vpry similar to the preceding, but the head and thorax are black ; 

 the latter is less companulate, more convex, and not impressed anteriorly; the 

 elytra are more dilated posteriorly, and diverge at the suture. The ieet and an- 

 tennae precisely as in C. chalybea. 



C. sphaericollis {Lytta syh. Say. Journ. Ac. Nat. Sc. 3,299,) must be 

 closely related to these two species, but will be distinguished by its more slender 

 form, and by the second joint of the antennae being rufous. 



19. L. femoral is, oenea, subnitida, supra fere glabra, thorace lateribus 

 parce punctato versus basin angustato, basi subreflexo, elytris subtiliter punc- 

 tulatis, pedibus cyaneis, femoribus (apice excepta) rufis, antennis nigris gracili- 

 bus. Long. -7. 



One male specimen. Louisiana ; Mr. Guex. Body slender, brassy somewhat 

 dull. Head sparsely punctured, truncate at base, a little narrowed behind the 

 eyes, which are large and prominent ; labrum green, deeply emarginate, strongly 

 punctured. Antennce, from the 5th to the lOth joints, gradually decreasing in 

 leuiith, increasing very slightly in thickness, slender, oblong, scarcely rounded ; 

 eleventh joint subconstricted, external part conical. Thorax as wide as the 

 head; slightly pentagonal, narrowed towards the base ; disc slightly flattened, 

 with several shallow impressions, sides sparselj- punctured, scarcely pilose ; base 

 slightly reflexed. Elytra a little wider than the thorax, finely and indistinctly 

 punctulate, with a scattered, scarcely perceptible pubescence. Legs blackish 

 blue, femora bright rufous, black at the apex ; the middle of the posterior tibias 

 is slightly rufous inferiorly ; middle tibiae short, slightly curved ; outer spur of 

 the posterior tibiae broad and concave. 



This species is very similar to the next, but the black tarsi, and finely punc- 

 tulate elytra will distinguish it ; the head is less quadrate and is not wider than 

 the thorax : the anterior tibiae are emarginate at the apex internally, which is 

 probably a sexual character. 



20. L. pol ita, aenea, subnitida, supra fere glabra, thorace capite angustiore, 

 lateribus parce punctatis versus basin angustato, bifoveato, basi subreflexo, ely- 

 tris subtilissime rugosis pedibus rufis, genubus tibiisque anterioribus nigris, 

 tarsis fuscis, antennis nigris gracilibus. Long. '65. 



Say, Journ. Ac. Nat. Sc. 3, 302. 



One female; Georgia. Body slendrr, brassy, somewhat dull. Head sparsely 

 punctured, a little dilated behind the eyes, which are prominent, squarely trun- 

 cate at base ; labrum blue, punctured, deeply emarginate. Antennae black, a 

 little lonicr than the head and thorax, scarcely thickened externally, joints ob- 

 long, equal in length, last joint longer, constricted, conical at tip. Thorax nar- 

 rower than the head, longer than wide, slightly narrowed towards the base; 

 sparsely punctured and slightly pilose towards the sides, disc somewhat flattened, 

 deeply bifoveate, basal margin reflexed at the middle. Elytra scarcely wider 

 than the head, parallel, very finely rugous, and obsoletely punctulate. Thighs 

 rufous, coxae, trochanters and knees black, anterior and middle tibiae black, 

 slightly rufous in the middle; posterior tibiae rufous, black at tip: tar.-i dark 

 fusrous; outer spur of the posterior feet broad, concave and obtuse. 



21. L. Sayi, olivacea fere opaca, capite thoraceque parce pilosis, subtiliter 



