AMERICAN COLEOPTERA. 25 



a. — Prothorax fulvous, with a brownish spot, anterior one-half or two-tliinls 



of elytra fulvous. Mo.; Ks. ; Tex. 

 /i. — Prothorax fulvous, sometimes with disc dark, eh-tr;i witli more or less 



extensive humeral sj^ot; {tvpe form). 

 y. — Elytra black, sometimes with a very small humeral spot ; lorothorax black, 

 . with margins narrowly fulvous, inces^MS Lee. L. Sufi. j Pa.j Mass. 



Black, sides of i^rothora.x fulvous; walls of anterior series of prothoracic cells 

 obliterated, only the medial carina remaining; jMsterior row of. cells as in 

 the preceding; viz., a narrow deep medial one, (-which is very finely earinate 

 at base), and two large lateral ones defined by the usual transverse ridge ; 

 the lateral cell is divided a transverse obtuse i^rominence into a deeyi im- 

 pression, and a strongh' marked subbasal groove. Scutel and elytra as 

 usual, tlie latter 4-costate the interspaces with double rows of quadrate cells: 

 trochanters large triangular, tibiae straight; antenna? of % long, slender, 

 scarcely serrate, third joint less tlian one-half as long as fourtli; of 9 

 shorter, stouter, subserrate, third joint one-half as long as fourth. Length 



.j— 7.5 mm. X. J.; Ga trilineattis Mels. 



a. — First discoidal costa of elytra indistinct; eyes of % larger than in tvjie. 



111.; Va.; Fla. 

 Black, prothorax fulvous, walls of anterior middle cell very indistinct, carina 

 acute, strongly marked, extending from apex to base, the posterior middle 

 cell liaving disappeared, transverse ridge strong, extending from margin to 

 dorsal carina, posterior lateral cells with a short transverse convexity con- 

 nected with the dorsal carina. Elytra 4-costate, interspaces with doulile 

 rows of quadrate cells; trochanters triangular, tibiae straight; antennae of 

 % slightly serrate, third joint broad, triangular, two-thirds as long as the 

 fourth ; of 9 ratlier stouter, but not otherwise specially diflerent. Length 

 .j.r)— 7..J mm. X. Y. ; Me.; L. Sup creiiatus Germ. 



PL.ATEKOS Bourgeois, (j Waterh.). 



Ill tliis genus tlie prothorax is without cells, sometimes slightly earinate 

 at the apex, always channeled or impressed behind the middle ; the sides 

 are strongly reflexed. but without the transverse ridge seen in the genuine 

 Eros. The scutel is flat, truncate behind. Elytra with roAvs of quadrate 

 cells sejiarated by nine narrow and usually equal slightly elevated lines ; 

 sometimes the alternate lines are a little stronger, so that they become 

 feebly 4-costate. The species of this genus are found on botli eoiitinents, 

 and are still very indistinctly defined. 



one, with which by modifications in different directions the other I'oriijs can be 

 readily harmonized: thus by completing the side walls of the anterior median 

 cell you have sculptilis, by obliterating the walls of the anterior median cell and 

 retaining the carina you have irilineatus ; by making the middle j)OSterior cell 

 vanish, but retaining a carina to re])resent its walls, you have crenatus ; finally 

 by obliterating the cell walls of the disc, retaining only the basal part of the 

 middle posterior cell, with the imperfect transverse elevated line connected with 

 it, you pass over to the genus Plateros. We have here evidently at comjilex in 

 which not only supposed generic characters are untenable, but the species are also 

 somewhat plastic and difficult to define. 



TRANS. AMER. ENT. SOC. IX. (4) MARCU, 1881. 



