268 LAMELLICOKNIA. 



This genus is founded to include a considerable number of species, homogeneous in 

 facies as well as in structural characters, which differ constantly from Antichira in the 

 form of the mandibles, from Thyridium in the size and shape of the scutellum (which 

 is one fourth the length of the elytra and triangular with flexuous sides), and from 

 Chlorota (sensu Lacordaire) in the well-developed mesosternal process. In the trun- 

 cated basal lobe of the thorax, also, it differs from the two latter genera, which are well 

 characterized by the same part being somewhat strongly rounded over the base of the 

 scutellum. 



l. Ptenomela gratiosa. (Tab. XV. fig. 12.) 



Antichira gratiosa, Sharp, Journ. Linn. Soc., Zool. xiii. p. 183 '. 



Hab. Nicaragua, Chontales (Belt \ Janson) ; Panama, Chiriqui (Trotsch), Bugaba 

 (Champion). 



Chiriqui specimens are wholly apple-green, and lack the reddish or coppery colour 

 of the elytral epipleurse which Sharp describes, and which all the Nicaraguan examples 

 possess. One of the latter is figured. 



THYRIDIUM. 



Thyridium, Burmeister, Handb. der Ent. iv. 1, p. 367 (1844), and iv. 2, p. 519 ; Waterhouse, Trans. 

 Ent. Soc. Lond. 1881, p. 545. 

 Fourteen species of this genus have been described, all restricted to Tropical America. 

 Its distinguishing characters are :— mandibles rounded (or very slightly sinuated) and 

 unarmed on their outer edge, thorax with rounded medio-basal lobe, and the scutellum 

 small and heart-shaped, or with curvilinear sides. 



1. Thyridium semicinctum. (Tab. XV. fig. 13.) 



Elongato-ovatuin, pomaceo-viride, elytris basi et marginis exteriore dimidio aurantiaeo-marginatis, supra 

 toto subtiliter strigulosum et punctulatum, pygidio grossius et transversius striguloso ; clypeo d breviter 

 subquadrato, margine antico vix arcuato paullo reflexo et incrassato, $ antice medio gradatim subacute 

 producto oblique reflexo nee incrassato ; tborace post dimidium rotundato-dilatato, postice perparum antice 

 recte angustato, angulis posticis distinctis paullo obtusis, lobo basali perparum producto rotundato, mar- 

 gine utrinque usque ad angulum leviter sinuato et depresso ; elytris margine laterali dimidio basali leviter 

 incrassato, intus stria tenui delimitato, dimidio apicali lam. Mesosterni processus crassus, subcylindricus, 

 inclinatus. J • Tarsi antici ungue majore fisso, 4 posteriores unguibus simplicibus ; pygidio apice breviter 

 conico. $ . Tarsi omnes ungue majore furcato ; pygidio piano, apice parum declivi. 



Long. 38 millim. rf S • 



Hab. Panama, Chiriqui (Trotsch), Volcan de Chiriqui 4000 to 6000 feet (Champion). 



CHLOROTA. 



Chlorota (partim), Burmeister, Handb. der Ent. iv. 1, p. 359 (1844); Lacordaire, Gen. Col. iii. 

 p. 347. 

 Seventeen species of this genus have been described, peculiar, like the preceding 



