PLATAMUS. 547 
PLATAMUS. 
Platamus, Erichson, Naturg. Ins. Deutschl. iii. p. 329, nota (1845). 
This is a small genus of about six species, and is peculiar to Tropical America. 
Considerable confusion has occurred in connection with it, due not improbably to the 
fact that it was too briefly defined by Erichson, and that no species was described at 
the time. The genus is readily identified by the elongate hind legs, with dilated tarsi, 
of the males. It was placed by Erichson in the group Brontini, which has been quite 
properly divided by the American entomologists owing to its containing forms with 
closed as well as others with open acetabula. Platamus having the acetabula broadly 
closed behind comes into the Silvanine. 
The species, like so many others in the Cucujide, are excessively similar; indeed, 
had I not seen fair series of those found in our region, I should have looked on them 
as mere variations. The sexes being similar to an extent variable according to the 
‘species, renders it difficult to pronounce an opinion as to a single individual, Fortu- 
nately, in the case of all the species here enumerated, we have received specimens of 
both sexes. ‘They appear to be found beneath the bark of coniferous trees. 
1. Platamus mexicanus. 
Platamus mexicanus, Grouv. Ann. Soc. Ent. Fr. 1876, p. 490, t. 8. fig. 5°. 
Hab. Mexico}, Orizaba, Suapam (Sallé), Las Vigas, Amecameca (Hége). 
The female differs from the male by the apical portion of the elytra being dull and 
its punctuation somewhat obliterated, as well as by the simple hind legs. As in the 
other species of the genus, the sexes also differ slightly in the size of the thorax and in 
the development of its lateral prominences. 
We have received a small series varying in colour from ferruginous to black. 
2. Platamus grouvellei, sp. n. 
Depressus ; prothorace elongato, crebre punctato, lateribus parum undulatis, haud denticulatis ; elytris pube 
brevi subrecta parcius vestitis. 
Mas, nitidus; elytris fortius punctatis; pedibus posterioribus elongatis, tarsis articulis duobus dilatatis, 
elongatis. 
Fem., elytris opacis, seriatim fere subtiliter punctatis ; tarsis posterioribus simplicibus. 
Long. 6-63 millim. 
Hab. Mexico, Omilteme in Guerrero 8000 feet (H. H. Smith), Parada (Sallé), 
Huitzo (Hége). 
Thorax deeply, rather closely, and finely punctate; the sides in front for a 
short distance straight, then interrupted by a short lateral impression; behind this 
almost without denticulations on the lateral margin. Elytra with the punctuation 
obsolete at the apex. 
4A A* 2 
