of the Arnazon Valley. 255 



tomentosis; tliorace nudo, gvosse et confuse rugoso- 

 punctato ; elytris castaneis, subtiliter puuctulatis^ apice 

 utrinque bispinosis ; femoribus medio l^te rufis. 



Long. 1 un. 2 lin. — 1 un. 6 lin. $ $ . 



Agrees with Erichson's description of Criodion cas- 

 tanopterum in all points, except the broad clear red ring 

 round the middle of all the femora. It is possible, 

 therefore, that Erichson^s species may form a third and 

 distinct one of this group. 



Hah. — Upper and Lower Amazons ; in the same situa- 

 tions as 8. puncticoUe. 



3. Sphallenum tuberosum, n. sp. 



Minus elongatum et vix convexum, nigi'o-fuscum, gla- 

 brum, nitidum, antennis scutello lateribusque pectoris 

 leviter tomentosis ; capite thoraceque impunctatis, hoc 

 tuberibus magnis circa 1 3 notato, toto leevi, polito ; 

 elytris vix punctulatis, apice utrinque bispinosis ; pedibus 

 piceo-rufis, femoribus medio et apice tibiisque basi fuscis 

 exceptis. 



Long. 1 un. 2 lin. 



Eah. — Tapajos.* 



Genus Xestia. 



Serville, Ann. Soc. Ent. Fr. 1834, p. 16 ; Lacord. 

 Gen. viii. 271. 



Restricted to those species which have the intermediate 

 sockets quite closed, and the middle and posterior femora 

 and tibiae without spines at the apex. 



* Criodion erythropus (Lticas, in Voy. cle Casteln. p. 187, pi. xi. f. 6), 

 from South Brazil, will, according to the views of Lacordaire (Gen. viii. 

 271, note), which I have here adopted, require to be separated from 

 Criodion, on similar groimds to those on which Sphallenum is instituted. 

 The genus may be termed Butheriurriy with the following characters : — 



BuxHEEiuM, nov, gen. 



Corpus oblougum, nudum. Caput tuberculis antenniferis basi late 

 separatis ; antennis articulo 4to (utroque sexu) baud 5to breviori. Fe- 

 mora apice simplicia, tibiis intermediis et posticis apice extus spinosis. 

 Acetabula intermedia anguste hiantia. 



Type. B. erythropus, Lucas, loc. cit. 



