COEEOPTERA. 543 



Paussus proper, has only two joints to the antennae, the second very large anil compressed. 

 Ilylotorus, Dalm., composed of a single species apparently with ocelli, and with theantenna: scarcely longer than 

 t!ie head, and 2-jointed. 

 Cerapterus, Swed., has the antennae 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 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.] 



Vsoa, 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.] 



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



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

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



The second principal genus, — 



MONOTO.MA, — 



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. 



Synchita, 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 antennas much 

 longer than the second ; the body nearly oval or parallelepiped, and the elytra not truncate behind. [G histeroides, 

 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. 



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

 by a narrowed part. Cerylon f.icipes [and other small species, of which Aube" has given a monograph in the 

 An/tales 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. 



Lyctug 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. snbterranca. 



Iiitoma, Herbst., differs in having the body long, narrow, depressed. [B. crcnata, 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 



M YCETOPHAGUS, — 



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. 



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

 club of the antennae commencing at the sixth or seventh joint. [M. ijuadrijmxtttlatus, anil several other species of 

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



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

 globular. 



Meryx, Latr., has the maxillary palpi exserted, and terminated by an enlarged joint, of a reversed triangular 

 form, [M. rngosus, Latr., New Holland.] 



Dasyccnis, Brongii., has 3-jointed tarsi ; theantenna; have all the intermediate joints capillary, nml very set. 

 the abdomen is nearly globular. 



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

 A liiili i^ Bubipiadrate, or subovate ; the liasul joint of the antenna' is very thick. [L. jmrratus, and other species 

 of minute insects, having domestic habits.] 



Silvanut, has the body nearly linear, the thorax longer than broad, and as broad as the base of tlieehtia; the 

 palpi aearly filiform. [7'. dentatut, a small Hat insect, often found floating in tea ami coffee, introduced with ttie 

 sugar.] 



In others the mandibles are entirely exposed, and large ; the body often narrowed and depressed. These insects 

 compose the genus— 



