MEGASUS.— PEASONA. 321 



MEGASUS. 



Body oblong-ovate ; head elongate ; eyes large, entire ; palpi filiform, terminal joint acute ; antennae as long as 

 the body, slender, filiform ; thorax transverse, with a laterally interrupted basilar groove ; elytra irregu- 

 larly punctured ; tibiaj longitudinally sulcate, the posterior ones mucronate ; claws appendiculate ; pro- 

 sternum very narrow : anterior coxal cavities open. 



The species for which I am obliged to erect this genus has the general shape and 

 appearance of a Lactica, from which it differs, as well as from other allied genera, by 

 the very long and slender antennae in connexion with the thoracic groove, which is 

 sinuate, and not limited at the sides by a longitudinal fovea, as in Lactica and 

 Diphaulaca, but interrupted at some distance from the lateral margin, each end being 

 directed obliquely upwards. 



l. Megasus bimaculatus. (Tab. XIX. fig. 12.) 



Testaceous ; antenna? (the basal joint excepted), tibiae, and tarsi black ; elytra testaceous,, scarcely visibly 

 punctured, a round small spot at the base and a narrow transverse band, interrupted at the sides, black. 



Length 2 lines. 



Head impunctate, frontal tubercles not strongly raised, the carina very swollen ( c? ), more flattened in the other 

 sex ; antennae black, the first joint testaceous, slender, and curved, second one half the length of the 

 third, fourth and following joints very slender and elongate, and reaching to the end of the body ; eyes very 

 large and distinctly reticulate ; thorax twice as broad as long, the sides straight, anterior angles obtuse, 

 posterior margin slightly rounded, surface impunctate, with a distinct transverse groove, the sides of 

 which are directed obliquely upwards, but do not extend to the lateral margin; scutellum trigonate; 

 elytra slightly widened behind, testaceous, extremely finely and closely punctured, a small round spot at 

 the base near the scutellum, and a short, narrow, transverse band at the middle, not extending to either 

 margin, black. 



Eab. Guatemala, Senahu in Vera Paz (Champion). 



The antennae in the female are slightly shorter than in the male;, but in other 

 respects I cannot find any difference, with the exception of the carina, as pointed out 

 above. 



b. Anterior coxal cavities closed. &■ 



PEASONA. 

 Prasona, Baly, Jouro. of Entom. i. 1861, p. 300. 



The genus Prasona (Mr. Baly has written the name in his collection Prasonia, and 

 has subsequently described another species under this name in the * Annals of Nat. 

 Hist.,' 1878) was founded by its author on a Mexican species of rather large size and 

 pale-green colour. In its general appearance it resembles the genus Haltica, also in 

 the shape of its thoracic groove ; the closed coxal cavities and differently made antennae 

 separate the genus Prasona sufficiently from the former. Mr. Baly described the 

 posterior tibiae as armed with two teeth or spines, which is certainly a mistake, as only 

 a single spine is present, which has already been pointed out by Von Harold (Coleopt. 

 Hefte, xiv. p. 33). A more important structural character, however, and which has 

 been overlooked by the author, is the presence of a small spine at the apex of all the 



biol. CENTE.-AMEE., Coleopt., Vol. VI. Pt. 1, October 1884. % t 



h I' 

 , b 



