BRENTHUS. 67 
and San Gerénimo in Vera Paz, El Tumbador, El Reposo, Volcan de Atitlan, Pantaleon, 
Capetillo (Champion); Nicaracua, Chontales (Belt, Janson) ; Costa Rica (Van Patten), 
Volcan de Irazu 6000 to 7000 feet (Rogers); Panama, Bugaba, Volcan de Chiriqui, Tolé, 
Taboga Island (Champion). 
The fine series before me of this species does not exhibit much variation except in 
size, and in the dentation of the posterior femora. ‘The thorax is sometimes entirely 
black, sometimes red along the middle. 
B. mexicanus is the only one of our species that has two teeth on the posterior 
femora of the male: this character is, however, subject to variation. The basal tooth is 
sometimes very long, rarely it is entirely absent; specimens may be found in which it 
exists only as a minute granule; the size of this tooth is, to a great extent, correlative 
with that of the indvidual, and it is only in the smallest examples that it is completely 
wanting. 
It seems highly probable that Brenthus peninsularis, Horn, from Lower California, 
belongs to the same species. 
6. Brenthus difficilis. 
Brenthus difficilis, Boh. in Schénh, Gen. Cure. v. p. 530°. 
Niger ; elytris flavo-lineatis, interstitio quarto linea valde elongata basali, interstitio tertio linea brevi 
subapicali. 
Long. 16-48 millim. 
Hab. Mexico}, Etla, Toxpam, Juquila (Sai/é), Mochitlan in Guerrero (Harford), 
Omilteme in Guerrero (H. H. Smith). | 
This species seems to be rare; it may be readily distinguished from B. mexicanus by 
the absence of the outer yellow stripe of the elytra, and by the hind femur of the male 
having only a single tooth. ‘The groove on the prothorax is distinct only on the basal 
half; there is sometimes a yellow spot on the eighth interstice about one-third of the 
length from the shoulder. In size B. diffictlis varies greatly: of a magnificent pair 
from Toxpam the male is 48 millim. long, and the female about 40; all the other 
- individuals, twelve in number, are very much smaller, and one or two attain only 
16 millim. | 
7. Brenthus rufescens, sp.n. (Tab. III. fig. 4, .) 
Rufus, subtus rufo-niger ; pedibus nigro-variegatis, antennis nigris; prothorace antrorsum transversim rugoso, 
sulco dorsali integro. 
Long. 35-42 millim. 
Hab. Costa Rica, Volcan de Irazu 6000 to 7000 feet, Rio Sucio (Rogers). 
'This insect is readily distinguished from the allies by the unicolorous upper surface, 
and by the thorax being sulcate from the base to the apex. The antenne are black ; 
the legs are black in larger part, but both femora and tibie are red, to a greater or less 
KK 2 
