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A N N E L L I D JE. 



slender, all five jointed, the penultimate joint simple. 

 Only three species have yet been found, and they 

 were detected in the environs of London. 



A. LEIODES (Latreille). Palpi scarcely filiform ; 

 maxillary with the terminal joint nearly cylindrical and 

 acuminate, the preceding minute labial rather shorter, 

 with the apical joint nearly ovate ; mandibles some- 

 what protruded, acute. Antennae, with the three basal 

 joints nearly cylindrical, the third rather the longest, 

 the three following short, nearly globose, the remain- 

 der forming a five-jointed club, the second joint of 

 which, or the eighth of the antennae, is very minute, 

 and the terminal, or eleventh, large and subovate ; 

 tibiae compressed, externally spinose ; posterior some- 

 times bent ; tarsi, four anterior five-jointed, slightly 

 dilated in the males, two posterior four-jointed. 



This genus is rather an extensive one, but the 

 species are far from abundant in Britain, only twenty- 

 six species being described by Stephens. They 

 differ considerably among themselves, but may be 

 at once distinguished from the other genera of this 

 family by the minute eighth joint of the antennae, or 

 the second of the capitulum. The species are found 

 in Boleti, Agarici, beneath the bark of trees, putrid 

 wood, damp banks, &c. 



A. AGATHIDIUM (Illiger). In this genus the palpi 

 are filiform ; maxillary with the last joint conic ; labial 

 small ; mandibles with the apex acute ; antennae 

 short, with a subovate club ; head rather large, in- 

 flexed ; thorax with the angles rounded, large, the 

 sides inflexed ; body globose, hemispheric, capable 

 of being contracted into a round ball ; elytra entire, 

 inflexed laterally ; legs short. 



The Agathidiutn resembles Leiodes in several re- 

 spects, but may be readily known by the structure 

 of the antennas, the eighth joint not being smaller 

 than the seventh, and the three last forming a sub- 

 ovate club, which, however, varies a little in the 

 different species ; and from the facility these insects 

 possess of rolling themselves up into a ball when 

 alarmed. They inhabit putrid wood and fungi, and 

 may be occasionally found in sand and gravel pits, 

 into which they fall by accident. 



Twelve species are described by Stephens, most 

 of which have been found near London. 



Genus CLAMBUS (Fischer). Trophi minute ; an- 

 tennse as long as the thorax, slender, pilose, the two 

 last joints large, oblong, forming a club ; head large, 

 nearly or quite as broad as the thorax, rounded an- 

 teriorly ; thorax transverse, the lateral margins more 

 or less attenuated ; elytra very convex, and gibbous 

 anteriorly, attenuated, and declining posteriorly, the 

 apex rounded ; body contractile into a ball ; legs 

 short ; tibiae slender, slightly pilose ; tarsi obscurely 

 articulated. 



Like Agathidium, the species of this genus have 

 the power of contracting themselves into a ball when 

 alarmed. From the genus just mentioned they may 

 be known by the great width and bulk of the head, 

 and by the club of the antennas being composed of 

 two joints only, a structure which also obtains in the 

 genus Orthoperus : but in that genus the head is 

 small, the elytra but slightly gibbous, and somewhat 

 truncate posteriorly. As in the kindred genera, the 

 species are found beneath putrid leaves and wood, 

 or in fungi, and in sand and gravel pits, &c. Owing 

 to their extreme minuteness, and the want of speci- 

 mens, we have not been able to detail their generic 

 character? so completely as could be wished. 



Genus CLYPEASTER (Andersch). Trophi very mi- 

 nute ; antennas rather slender, the three terminal joints 

 forming an elongate ovate compressed club ; head 

 minute, concealed beneath the anterior margin of the 

 thorax, which is produced and semicircular ; the 

 thorax itself semioval, pubescent; scutellurn minute, 

 rounded ; elytra ovate, slightly convex, the apex 

 obtusely rounded, pubescent ; legs slender, the pos- 

 terior pair remote from the intermediate ; tarsi slen- 

 der, four-jointed, posterior with the terminal joint 

 very long and curved. 



The minute head of the insects of this genus, 

 which is concealed beneath the thoracic shield, dis- 

 tinguishes it from clambus, from which genus it also 

 differs by its depressed body, triarticulate clava of 

 the antennas, and semi-oval thorax ; from Serico- 

 derus, which has also the capitulum tri-articulate, the 

 rounded apex of the elytra removes it ; and Ortho- 

 perus has the head minute, not concealed beneath 

 the thorax, and a biarticulate capitulum. The only 

 indigenous species is found beneath the bark of trees, 

 &c. at Dareuth Wood. 



Genus SEKICODERUS (Stephens). Trophi very mi- 

 nute ; antennae rather elongate, slender, the three last 

 joints forming an elongate capitulum ; head small, con- 

 cealed beneath the anterior margin of the thorax, which 

 is slightly produced ; thorax sericeous, broad, sub-tri- 

 angular, the hinder angles somewhat acute ; elytra 

 sericeous, slightly gibbous anteriorly, alittle depressed 

 behind, the apex distinctly truncate ; legs slender ; 

 tarsi obscurely articulated. 



This genus is at once known from the rest of the 

 family by its truncate elytra, combined with the tri- 

 articulated capitulum of its antennae, minute head, 

 and projecting anterior margin of the thorax, exclu- 

 sively of other characters. 



ANNELLID^E (from anneUug,* little ring). A 

 class ofinvertebrated animals, and the first of the four 

 into which the articulata, or jointed animals, are divided 

 in Cuvier's Animal Kingdom. See ARTICULATA. In 

 common language they are known as worms, leeches, 

 and other names, according to the species and the 

 habit. The annellidae must not be confounded with 

 the unnulosu of some systematists, which includes all 

 the four orders of articulated animals, and is there- 

 fore synonymous with that term. Annulose means 

 that the body of the animal, taken in the direction of 

 its length, is divided into a certain number of rings, 

 segments, or joints, of which the principal ones are the 

 head, the breast, and the belly : the distribution could, 

 however, be much better described upon other princi- 

 ples than that of being so divided into annuli, which, 

 in very many instances, have little resemblance to 

 rings, being generally different from each other on the 

 upper and under sides of the body. The annellidae 

 are free from those objections. Their rings surround 

 the body, they are very small, and proportionally nu- 

 merous. They seem also, in all the known species, 

 to be the only substitute which the animals have for 

 a skeleton ; and they are the chief, indeed the sole, 

 organs of locomotion, either by their own edges, or 

 by moans of small but stiff bristles, with which many 

 of the species are furnished, singly or in little tufts. 

 The power of expansion or contraction which those 

 rings possess is truly wonderful, as may be seen in 

 the common earth -worm, the leech, and especially the 

 horse-leech. In other countries there are species 

 which have this property in a still greater degree. 

 Those leeches which are so annoying in Ceylon, 



