378 LAMELLICOKNIA. 



than the straight truncature specified by Westwood as the distinctive character of 

 /. sommeri, as Mexican examples vary much in this respect, the apex being sometimes 

 strongly sinuated. 



DIALITHUS. 

 Dialithus, Parry, Trans. Ent. Soc. Lond. v. p. 181 (1849). 



This genus contains a single species, which, so far as at present known, is peculiar to 

 Central America. 



1. Dialithus magnificus. (Tab. xxill. fig. 17.) 



Dialithus magnificus, Parry, Trans. Ent. Soc. Lond. v. p. 181, t. 18. fig. 4\ 

 Hab. Mexico 1 ; Nicakagua, Chontales {Belt). 



Mr. Belt obtained three examples of this superb insect at Chontales, in one of which 

 the elytra and legs are tawny-red instead of black as in Parry's type specimen. In the 

 male the anterior tibia? are abruptly narrowed near the apex ; without upper tooth, and 

 the apical tooth is much less prolonged than in the female. 



TRIGONOPELTASTES. 



Trigonopeltastes, Burmeister, in Germans Zeitschr. ii. p. 406 (1840); Handb. der Ent. iii. p. 747. 

 Six species of this exclusively American genus have been described, one South 

 Brazilian excepted, all from the United States and Mexico. 



1. Trigonopeltastes deltoides. 



Trichius deltoides, Newman, Entom. Mag. v. p. 169 \ 



Trigonopeltastes deltoides, Burm. Germ. Zeitschr. ii. p. 407 ; Handb. der Ent. iii. p. 748 \ 



Hab. Mexico 12 . 



This, the largest species of the genus, is not contained in our collection. 



2. Trigonopeltastes archimedes. 



Trigonopeltastes Archimedes, Schaum, in Germar's Zeitschr. iii. p. 235 ' ; Burm. Gen. Ins. no. 34, 

 fig- 3 ( S ) ; Handb. der Ent. iii. p. 749 2 . 

 Eab. Mexico 1 2 , Acapulco {Edge). 



3 . Pygidium fere planum ; venter medio subglaber ; tibiae anticse bidentatse, medio extus late rotundatse. 

 2 . Pygidium prope apicem convexum ; venter medio (et metasternum) dense albido-villosus ; tibias anticse 

 graciliores acutiusque bidentatas. 



This species is distinguished by its narrow oblong form, the great length of the sides 

 of the thorax after the antemedian dilatation, and the broad quadrate black circum- 

 scutellar (including the scutellum) spot of the elytra, on the hinder margin of which a 

 short, sometimes interrupted, fascia crosses the suture. The raised triangular plate of 

 the thorax and adjoining parts are impunctate. 



