PLUSIOTIS. 279 



This and other species of Plusiotis (as well as Thyridium and various Antiehirm) were 

 met with flying in the hot sun about the tops of trees on the margin of a lagoon in the 

 dense forest ; numerous living and dead specimens of these (as well as vast numbers of 

 Dynastidse and other Lamellicornia) were also found submerged in the water or cast up 

 on the banks [Champion). 



6. Plusiotis optima. (Tab. XVI. fig. 10.) 



Elongato-ovata, prope elytrorum basin valde convexa fere gibbosa, politissime aurescenti- vel igneo-cuprea, elytris 

 certo situ leviter fulvo-translucentibus, subtus cum antennis, epipleuris, pygidio et pedibus rufescenti- 

 luteis, tarsis euprascentibus ; capite sat sparsim punctate, clypeo semiovato margine leviter reflexo ; 

 tborace brevi et lato, ante medium valde angulatim dilatato, lateribus antiee et postice sinuatis, angulis 

 anticis prolongatis acutis, posticis acutis, aulculo marginali lato et profundo, margine postico sulculo medio 

 late interrupto ; elytris laevibus vix perspicue obsolete striatis, margine laterali usque ultra medium paullo 

 incrassato-reflexo, callo apicali valido subconico ; pygidio sparse punctulato, convexo, margine apicali 

 supra anum alte elevato medio acute reflexo ; pedibus fere impunctatis ; mesosterni processu valde 

 elongate, spiniformi. 



Long. 26 millim. S • 



Hab. Costa Rica ( Van Patten). 



One example only, from its short, squarely emarginated, apical ventral segment 

 undoubtedly a female. The species differs in many respects from all its congeners, and 

 from the nearly immarginate base of the thorax might be considered to approach 

 Thyridium or Ptenomela more nearly than any genus of the Pelidnota group, but the 

 marginal sulcus near the posterior edge of the thorax is scarcely impressed in other 

 species of Plusiotis. The rich red-golden hue of the upper surface and mirror-like 

 polish make it one of the most conspicuous species of a genus remarkable for metallic 

 splendour. 



7. Plusiotis batesi. 



Plusiotis batesi, Boucard, Proc. Zool. Soc. 1875, p. 119, t. 23. fig. 6 1 , and 1878, p. 293 \ 



Hob. Costa Eica {Van Patten), Volcan de Irazu 1 2 . 



Twelve examples, both sexes. The clypeus in the male is obtusely rounded in front, 

 and in the female a little more elongate and produced, with the slightly refiexed apical 

 margin more or less sinuated. The mesosternal process is rather short, but acute, and 

 not conical or thick vertically. It is a large (32 millim.) and somewhat narrowly 

 oblong species, with relatively narrow thorax widened before the middle. The colour 

 in the fresher examples is more silvery than in P. resplendens, but less purely white 

 than in P. ehrysargyrea. 



8. Plusiotis ehrysargyrea. (Tab. XVI. fig. 9.) 



Pelidnota ehrysargyrea, Salle, Ann. Soc. Ent. Fr. 1874, p. 361 \ 



Plusiotis ehrysargyrea, Boucard, Proc. Zool. Soc. 1875, p. 120 2 , and 1878, p. 294. 



Hab. Costa Eica 12 (Van Patten, in coll. Salle); Panama, Volcan de Chiriqui 4000 

 to 6000 feet (Champion). 



