of the Amazon Valley. 397 
1. Steirastoma depressum, Fabr. 
Cerambyx depressus, Fabr. Ent. Syst. i. ii. 260, 32. 
St. breve, depressum, postice valde attenuatum, nigrum, tenuiter 
griseo tomentosum : thoracis lateribus quinquetuberculatis, dorso 
depresso tricarinato: elytris subtrigonis, carinis centro-basalibus 
valde curvatis ramulum suturam versus emittentibus, apice spi- 
nosis: pedibus nigris, cinereo obscure variegatis: corpore subtus 
nigro, nitido, lateribus ochraceo tomentosis. Long. 7—! 1 ln. dQ. 
Head black, scantily clothed with grey tomentum, sparingly 
punctured with three raised longitudinal lines, the lateral ones. 
flexuous, the central one straight and running from the vertex 
to the edge of the epistome. Antennz half as long again as the 
body in the g, a little longer than the body in the ?, black, the 
bases of the joints ashy; the first joint in the dof an irregular 
clavate shape, rugose, tuberculated at the apex. Thorax punc- 
tured near the fore and hind margins; the sides have each five 
tubercles, two anteriorly and three on the moderately produced 
lateral prominence ; the dorsal carine are smooth, and shining 
black, the lateral ones being flexuous, interrupted, and tubercu- 
late. The elytra are clothed with thin ashy tomentum, streaked 
and spotted with black; the centro-basal ridges are granulated 
and strongly curved, the posterior end of the curve emitting a 
short branch towards the suture; afterwards each is continued 
as a flexuous and smooth keel to the apex: the apex itself is 
produced into a strong tooth or spine, which varies in length in 
different individuals. The fore legs of the gare much elon- 
gated. 
This is a common Guiana species, and is generally distri- 
buted throughout the Amazon region, being found everywhere 
in new clearings, sometimes under the loose bark of trees. Like 
all the other species of the genus, it is sluggish in its motions, 
and feigns death when touched, bending its legs in a rigid posi- 
tion, and falling to the ground. As the Fabrician description is 
insufficient, and his name has been referred to a nearly allied 
but distinct South Brazilian species, I have thought it necessary 
to give a lengthened diagnosis. According to the British Museum 
collection, the C. depressus of Fabricius is the same as the C. 
brevis of Sulzer, an earlier author, and applies to the larger spe- 
cies of South Brazil above mentioned. I think, however, the 
description of Fabricius quoted above cannot apply to any other 
than the one I have described. It is probable, also, that 
Sulzer and the other old authors had the Guiana species 
in view in their C. brevis; for the productions of Brazil were 
not known in Europe at the time they wrote. I do not adopt 
Sulzer’s name, however, because it is likely that the C. depressus 
