_ HETEROCERUS. 117 
fab. Guatemata, Panzos and Teleman (Champion). 
By its minute size, fine sculpture, and pallid colour this species greatly resembles 
the European HT. flavidus, from which, however, it is quite distinct by the immarginate 
base of the prothorax.; the front tibie are broad, and the spines with which they are 
armed are rather broader and less acuminate than in other species of the genus. 
I have seen only two individuals: in one of them the middle of the metasternum and 
ventral segments is a little infuscate. 
2. Heterocerus armatus. (Tab. IV. fig. 4.) 
Fusco-niger, pube densa brevissima vestitus, fere opacus, elytris maculis octo rufis; antennarum basi pedibusque 
testaceis, tibiis nigro lineatis ; prothorace elytris paulo latiore, densissime subtiliter punctato, basi utrinque 
ad angulos posteriores marginata; elytris obsolete striatis, subtiliter punctatis ; labro apice emarginato- 
truncato. , 
Mas mandibulis valde prolongatis, apice acuminato, ante apicem superne dente elongato armatis ; labro elongato, 
lateribus sinuatis. . 
Long. 23, lat. 3 lin. 
Hab. Mexico, Tuxtla (Sad/é). 
The form of the labrum and mandibles in the male of this species is very remarkable: 
the apical half of the former is considerably narrower than the basal portion, the narrow 
apex being nearly truncate, the sides at the base are rounded ; some portions of the 
maxillz project beyond the labrum, and cause this to appear longer than it really is, 
and as if it were acuminate; the detached free membranous lobe is quite separate 
from the body of the mandible, and appears as if it sprang from the interior of the 
mouth ; though it is very detached, it is easily overlooked, owing to its being perfectly 
transparent. The female has the parts of the mouth of normal structure. ‘The pale 
markings of the elytra consist of four detached spots on each, and at the apex the 
lateral margin is narrowly pale. 
I have seen only a single male and two females, in very bad preservation. H. gnatho, 
Lec., from California, is no doubt a species allied to this. 
3. Heterocerus simplex. 
Sat elongatus, opacus, fuscus, elytris margine laterali et signaturis magnis, antennarum basi pedibusque 
testaceis, tibiis fusco-testaceis; prothorace subtilissime punctulato, angulis posterioribus marginatis ; 
metasterno mutico. 
Long. 23, lat. 2 lin. 
Hab. Mexico, Vera Cruz (Hége). 
Mandibles much curved externally, short, and stout, at the apex inwardly with three 
very distinct, equal, and equidistant teeth, the apical one of the three being the point 
of the mandible. Labrum short and broad, but little ciliate, so that in front it is seen 
to be very distinctly emarginate. The thorax is extremely finely punctate, and its base 
on each side is very finely marginate; the side itself, however, is almost immarginate. 
