Orders. COLEOPTERA. 543 



Paussus proper, has only two joints to the antenn», the second very large and compressed. 

 Hylotorttg, Dalm., composed of a sing^le species apparently with ocelli, and with the antennae scarcely longer than 

 the head, and 2-joiuted. 

 Cerapterus, Swed., has the antennas 10-jointed and perfoliated. 



2. Those which have only 10-jointed antennae, 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 tliree terminal joints forming a perfoliated 



mass compose that of — 



BosTRicHUs, Geoffr. 



So*<ricAM« 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, fomid in fungi.] 



Sphindus, scarcely appears to me to differ from the last. 



Nemosoma, Desman, has the body long, linear, and the mandibles robust andexserted. [N. elongata, a singular 

 small and very rare British species, found under the bark of old palings.] 



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 mandible.s, not prominent. 



Synchita, Helw., has not the front of the head prolonged, and the two basal joints of the antennai 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 nevirly oval or parallellipiped, and the elytra not truncate behind. [C. histeroides, 

 a small species found under the damp bark of trees.] 



Rhyzophagiis, Herbst., differs from Cerylon in its narrow elongated form and elytra truncate at the tip ; the 

 tarsi appear to me pentanierous. 



Monotonia, Herbst., differs from all the preceding in having the head as large as, and separated from, the thorax, 

 by a narrowed part. Cerylon )uipes [and other small species, of which Aub^ has given a monograph in the 

 Annales de Soc. Entomol. de France], 



3. Those which have eleven distinct joints to the antennae; 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 antennae consists only of two joints. These form the genus 



Lyctus. 



Lyctus proper, Fab., has the mandibles and basal joints of the antennae exposed. 



Diodesma, Megerle, has the basal joint of the antennae hidden by the side of the head : the body oval, oblong, 

 convex. D. subterranea. 



Bitoma, Herbst., differs in having the body long, narrow, depressed. [B. crenata, a small British species, found 

 under the bark of trees.] 



In the others the three or four terminal joints of the antennae form the club, the last being larger than the pre- 

 ceding joints. 

 • In some the mandibles are concealed or scarcely visible ; these are the genus 



Mycetophagus, — 



Colydium, Fabr., has the antennae scarcely longer than the head, and inserted beneath the advanced sides of the 

 head, and terminated by a perfoliated mass. 



Mycetophagits proper, has the antennae at least as long as the thorax, the body oval, thorax transverse, and the 

 club of the antennas commencing at the sixth or seventh joint. [M. quadripustulatus, and several other species ot 

 small size, found under old stumps of trees, bark, &c.] 



Tripkyllus, Meg., has the club of the antennae shorter, and formed suddenly by the last three joints, thelast being 

 globular. 



Meryx, Latr., has the ma.xillary palpi exserted, and terminated by an enlarged joint, of a reversed triangfular 

 form. [3/. rugosiis, Latr., New Holland.] 



Dasycerus, Brongn., has 3-jointed tarsi ; the antennae have all the intermediate joints capillary, and very setose; 

 the abdomen is nearly globular. 



Latridius, Herbst. has the palpi very short, pointed at tip ; the head and thorax narrower than the abdomen, 

 ■which is subquadrate, or subovate ; the basal joint of the antennae 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 elvtra; the 

 palpi nearly filiform. [T. dentatus, a small fiat 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. Tliese insects 

 amipose the genus— 



