COLEOPTERA. 
543 
Paussus proper, has only two joints to the antennse, the second very large and compressed. 
Hylotorus, Dalm., composed of a single species apparently with ocelli, and with the antennse scarcely longer than 
the head, and 2-jointed. 
Cerapterus, Swed., has the antennse 10-jointed and perfoliated. 
2. Those which have only 10-jointed antennse, and the maxillary palpi are not narrowed to the tips, 
but are of equal thickness throughout, or thicker at the tips ; the joints of the tarsi are always entire 
They are divisible into two principal genera ; those with the three terminal joints forming a perfoliated 
mass compose that of — 
, Bostrichus, Geoffr. 
Bostrichus proper, has the body cylindrical, the thorax forming a kind of hood over the head. The species are 
found in old wood and timber. \B. capucinus, a rare British species.] 
Psoa, Fabr., has the body narrower, and thorax flat. 
Cis, Latr., has the body oval, depressed, or but little elevated ; the last joint of the tarsi much longer than the 
others ; the head of the males often horned. [Many minute species, found in fungi.] 
SpMnduSf scarcely appears to me to dilfer from the last. 
Nemosoma, Desmar., has the body long, linear, and the mandibles robust and exserted. [iV. elongata, a singular 
small and very>are British species, found under the bark of old palings.] 3 
The second principal genus, — 
Monotoma,— 
Has the club (or tenth joint) of the antennae solid, and button-shaped ; the body is elongated, with the front of the 
head narrowed into an obtuse muzzle ; the palpi are very small, and, as well as the mandibles, not prominent. 
Sy nchita, Helw., has not the front of the head prolonged, and the two basal joints of the antennae are alike. 
Cerylon, Latr., has the front of the head produced into an obtuse triangle ; the first joint of the antennae much 
longer than the second ; the body nearly oval or parallellipiped, and the elytra not truncate behind. [C. Msteroides, 
a small species found under the damp bark of trees.] 
Rhyzophagus, Herbst., differs from Cerylon in its narrow elongated form and elytra truncate at the tip ; the 
tarsi appear to me pentamerous. 
Monotoma, Herbst., differs from all the preceding in having the head as large as, and separated from, the thorax, 
by a narrowed part. Cerylon picipes [and other small species, of which Aub^ has given a monograph in the 
Annates de Soc. Entomol. de France}. 
3. Those which have eleven distinct joints to the antennse ; the palpi filiform, or thickened at the 
tips in some, or slender at the tips in others, the tarsal joints are entire. 
In some of these the club of the antennse consists only of two joints. These form the genus 
Lyctus. 
Lyctus proper. Fab., has the mandibles and basal joints of the antennse exposed. 
Diodema, Megerle, has the basal joint of the antennae hidden by the side of the head : the body oval, oblong, 
convex. D. subterranea. 
I Bitoma, Herbst., differs in having the body long, narrow, depressed. {B. crenata, a small British species, found 
I under the bark of trees.] 
j In the others the three or four terminal joints of the antennse form the club, the last being larger than the]pre- 
,! ceding joints. 
i In some the mandibles are concealed or scarcely visible ; these are the genus 
Mycetophagus, — 
i Colydium, Fabr., has the antennse scarcely longer than the head, and inserted beneath the advanced sides of the 
li head, and terminated by a perfoliated mass. 
j| Mycetophagus proper, has the antennse at least as long as the thorax, the body oval, thorax transverse, and the 
I club of the antennse commencing at the sixth or seventh joint, [ilf. quadripustulatus, and several other species of 
j small size, found under old stumps of trees, bark, &c.] 
I Triphyllus, Meg., has the club of the antennse shorter, and formed suddenly by the last three joints, the last being 
! globular. 
1 Meryx, Latr., has the maxillary palpi exserted, and terminated by an enlarged joint, of a reversed triangular 
' form. [M. rugosus, Latr., New Holland.] 
Dasycerus, Brongn., has 3-jointed tarsi ; the antennse have all the intermediate joints capillary, and very setose ; 
1 the abdomen is nearly globular. 
j Latridius, Herbst. has the palpi very short, pointed at tip ; the head and thorax narrower than the abdomen 
i which is subquadrate, or subovate ; the basal joint of the antennse is very thick. [L. porcatus, and other species 
of minute insects, having domestic habits.] 
Silvanus, has the body nearly linear, the thorax longer than broad, and as broad as the base of the elytra ; the 
palpi nearly filiform. [T. dentatus, a small flat insect, often found floating in tea and coffee, introduced with the 
sugar.] 
] In others the mandibles are entirely exposed, and large ; the body often narrowed and depressed. These insects 
[ compose the genus — 
