ABACTRUS.—STEREODERMUS. 7 
in front of the coxa. Prosternum not sulcate. Tarsi strongly compressed, broad in 
one direction. 
Only one individual was found of this interesting little insect; it is no doubt of the 
male sex ; the antenne have much setosity on the lower surface. 
Group STEREODERMINA. 
The Trachelizides of Lacordaire should be divided into two groups: one, represented 
by Stereodermus, has the anterior tibize more or less excised, and the hind coxe more 
than usually distant from one another; while the other, including Trachelizus, has 
the anterior tibiz unnotched, and the hind coxe separated by only the width usual 
in the Brenthide. The group Stereodermina is here proposed for the first-mentioned 
forms. On the other hand, Lacordaire’s tribe Hephebocerides, consisting of two 
genera, Lonthocerus and Hephebocerus, should be suppressed ; Lonthocerus being placed 
in Stereodermina, Hephebocerus in Trachelizina. 
STEREODERMUS. 
Stereodermus, Lacordaire, Gen. Col. vii. p. 419 (1866). 
This genus of small Brenthide consists of one Mexican, one Antillean, and one 
South-American species, in addition to another recently added by Dr. Senna from the 
island of Engano in the Austro-Malayan province. 
I now describe sixteen species from our region. I have several Brazilian represen- 
tatives of the genus in my collection, all of which, except one, are distinct from our 
species and are undescribed. The sexes in Stereodermus have not yet been satisfactorily 
distinguished. I find that in certain individuals there is a slight mucronation of the 
internal faces of the apices of the middle and hind tibie. This is probably indicative 
of the male sex; and if I am right in this conjecture we may conclude that the sexes 
are extremely similar, but that the male is distinguished by the character mentioned, 
by a different sculpture of the last ventral plate, and by the prorostrum, or anterior 
part of the rostrum, being just perceptibly less elongate than it is in the other sex. 
The Stereodermi seem to be rather rare insects, as of our sixteen species only two are 
represented by a good series of examples. 
I arrange our species in two groups, distinguished as follows :— 
Rostrum short and broad, prorostrum not greatly longer than broad. (Tab. I. 
fig, 11.) 2. 2. 2. 2 ee see we ew we). 6Species 1-14. 
Greater portion of under surface of head dull front tibize very deeply 
notched. (Tab. I. fig. 6a.) . an toe ee ee 
Under surface of head entirely, or in greater part, shining ; tibial notch 
more or less shallow . . . . toe ee we ew ew ww ee «Species 7-14, 
Prorostrum longer and more slender, much longer than broad. . . . . . Species 15, 16. 
Species 1-6. 
