8 RHYNCHOPHORA. 
1. Stereodermus pygmeus. 
Arrhenodes pygmaeus, Gyll. in Schénh. Gen, Cure. i. p. 333 ‘ 
Cerobates pygmeus, Schonh. Gen. Cure. v. 2, p. 489°. 
Stereodermus pygmeus, Gemm. & Harold, Cat. Col. ix. p. 2705 *, 
Stereodermus brevirostris, Senna, Bull. Soc. Ent. Ital. xxi. p. 33°. 
Hab. Mexico!234, Playa Vicente, Toxpam, Orizaba (Sallé), Cerro de Plumas 
Jalapa (Hége), Motzorongo (Flohr); GvaTemata, San Juan in Vera Paz, Capetillo, 
Zapote, Las Mercedes (Champion); Panama, Volcan de Chiriqui (Champion).—Sovutu 
America, Boa Sorta (Sahlberg, Nov. 1850). 
If I am right in treating all the individuals before me as one species, S. pygmeus is 
variable as regards size, colour, sculpture, and some more important characters, such as 
the extension of the channel on the head and the form and sculpture of the terminal 
plate of the venter. I have not been able to discriminate the sexes with certainty, and 
I am therefore at present disinclined to distinguish more than one species. The 
descriptions extant are by no means sufficiently good to enable one to recognize 
exactly the insect that was before the describers’ eyes; but as all those who have dealt 
with the species have had Mexican examples before them, there is little doubt that 
the name should be ascribed to the only common Mexican species of the genus. 
The length varies from 4 to 7 millim.; the channel on the rostrum is sometimes 
abbreviated between the eyes, in other cases it is prolonged, as a more or less fine 
channel, to the back of the head. The eyes are moderately large and extend very 
nearly to the back of the head. The thorax bears a few very distant and minute 
punctures. The elytra have the sutural interstice shining; the second interstice 1s 
shining, but extends only about one-fourth of the length; the third interstice is 
depressed, fine, placed at the bottom of a groove, and is usually dull but sometimes 
shining ; the fourth interstice is not carinate, and the punctures by which it is separated 
from the third are not easily distinguished, outside it runs a series of punctures that 
are placed on the most elevated part of the wing-case; the fifth interstice starts from 
the shoulder but hecomes quite indistinct, to reappear again at the apex as a short 
carina; outside this the surface is shining and bears coarse punctures, but the longi- 
tudinal raised interstices are abbreviate. The terminal ventral plate is highly polished 
and is sometimes free from punctures, while in other cases it has some very large 
punctures, variable in number; the penultimate veutral plate is either truncate or 
rounded behind. 
Some of the following species are very similar to certain of the varieties of 
S pygmeus, but I think they are really distinct ; indeed, I shall not be surprised if it 
prove that there are more than one species amongst the specimens I have called 
S. pygmeus. Dr. Senna is now of opinion that his S. brevirostris is not truly distinct 
from S. pygmeus. His type represen's the ordinary form of the species. Some examples 
