40 
nulato-pimctatiS, fasciculis parvis pilorum orriatis, apice singulatim 
roturidatis. Long. lin. 
Head punctured, tomentose. Antennae half as long again as 
the body, ashy ; tips of the joints blackish. Thorax with very 
acute-pointed lateral tubercles, two obtuse dorsal ones, and a third 
behind, smaller, also obtuse; the surface coarsely punctured, 
pubescent and brown in colour. Elytra with moderately raised 
crested centro-basal ridges, the scutellar space between them 
densely and regularly punctured, violet-brown in colour; the 
rest of the surface is ashy-white, sparingly punctured ; each 
elytron has two or three incomplete raised lines, along each of 
which is a row of very small linear pencils of dark-coloured hair. 
Body beneath and legs black, clothed with ashy pile. 
This species I found at Caripi, near Para. It is closely allied 
to the preceding, and is probably a variety of it ; but its much 
smaller size, different coloration and punctation, give it so di- 
stinct a character that, in the absence of connecting links, I am 
obliged to treat it as a separate species. 
The present genus terminates the succession of generic forms 
which lead from the Acanthoderes type to that of Acanthocinus 
and Leiopus. I shall now return to a series of forms which ap- 
pear to have branched off from Acanthoderes, especially from 
those species resembling Pteridotelus in general structure. 
Genus Steirastoma, Serv. 
Serville, Ann. Soc. Ent. Fr. iv. 24. 
This is a well-defined genus, not very closely allied to any of 
the preceding. Its nearest relationship seems to be with those 
species of Acanthoderes which have slender fore tibise, rounded 
anterior acetabula, and closed acetabular sutures, tricarinate 
thorax, and prominent centro-basal ridges continuing as smooth 
carinae to the apex of the elytra. It differs, however, from 
Acanthoderes in the complex tuberculation of the sides of the 
thorax. Instead of a simple lateral conical tubercle or spine, as 
is usual in the Longicorn family, the thorax presents, on each 
side, an irregular prominence furnished with three tubercles. 
In some species this prominence is very strongly developed, and 
then two of the tubercles are carried to the apex, giving it a 
bifid appearance, the third remaining at the base beneath. All 
the species have, besides this tricuspid prominence, an acute 
tubercle on each side near the fore margin of the thorax ; and 
some present, in addition to this, a similar pointed wart on the 
side, some distance above it. The muzzle, although similar in 
shape to that of A. bivitta, is considerably longer and more 
