CHELIDONIUM. 211 



Antennae rather slender, filiform, about equal in length to the 

 body in the and a little longer in the d 1 ; the joints from the 

 fifth or seventh to the tenth angulate or dentate at the antero- 

 distal angle, third longer than the fourth, eleventh a little longer 

 than the tenth. Prothorax transverse, tuberculate at the middle 

 of each side. Elytra slightly and gradually narrowed backwards 

 from the base, separately rounded at the apex. Front and middle 

 legs moderately long, their femora subclavate ; hind legs much 

 longer, their femora gradually thickened, reaching to or beyond 

 the apex of the elytra in the <3 ; first joint of hind tarsus longer 

 at least than the second and third united. 



The structural characters that distinguish this genus from 

 Polyzonus, Casteln., are slight. They consist chiefly in the 

 distinctly angulated or dentate joints of the antennae and the 

 somewhat longer hind femora. The species with a few excep- 

 tions are destitute of yellow markings on the elytra, whereas 

 in Polyzonus nearly all the species are spotted or banded with 

 yellow. 



Lacordaire, labouring under an error in regard to the genus 

 Leontium of Thomson, placed Chelidonium in the same genus, 

 making it his section B. Leontium, Thorns., has as its type L. viride, 

 Thorns., a species from Japan (since described by Bates as Chlori- 

 dolum temte), and is really very closely allied to, and scarcely 

 distinct from, Chloridolum. 



233. Chelidonium argentatum. Dalm. (Cerambyx) Sdwnh. Syn. Ins., 

 App. p. 151 (1817). 



Dark metallic green, and for the most part dull, above ; the 

 underside of a brighter, glossier green, covered with a fine silvery- 

 grey pubescence ; legs and antennae dark blue or violaceous, some- 

 times partly green, the tarsi brownish black. Head densely 

 rugulose-punctate with a smooth, transverse, slightly depressed 

 space between the clypeus and front ; the front with a median 

 linear groove which extends to the vertex. Antennae a little 

 longer than the body in the 6 ; first joint nitid, densely punctate, 

 fifth to tenth each with a sharp oblique spine at the apex on the 

 anterior side ; third and fourth angulated at the apex. Prothorax 

 with a conical but rather obtusely pointed tubercle on each side ; 

 densely punctate and somewhat rugulose above, with a more 

 densely punctate and less rugulose opaque area along each side of 

 the middle, the rest subnitid. Scutellum smooth and glossy. 

 Elytra very densely and rather finely rugulose-punctate, and for 

 the most part dull ; rather narrowly rounded at the apex. Femora 

 finely and densely punctate ; the hind pair extending a little past 

 the apex of the elytra in the <3 . First joint of hind tarsus nearly 

 as long as the remaining joints united. Fifth abdominal segment 

 -of tf with a rather deep sinuate emargination posteriorly, the 



