CYCHLA CYCLOPS. 



'227 



the front of the head being elongated into a kind of 

 beak. Two other species, C. elongatus and attenuatus, 

 have been mentioned as inhabitants of this country, 

 but without sufficient authority. 



CYCHLA, a genus ofspinous-finned fishes, belong- 

 ing to the family LABROID^E, which see. 



CYCLAMEN (Linnaeus). A genus of European 

 tuberous rooted herbs, cultivated for the beauty of 

 their flowers. The genus belongs to Pentandrin 

 Monogynia, and to the natural order Primulacecc. 

 Generic character : calyx bell-shaped, divided half 

 way down into five parts ; corolla base swollen, throat 

 a little prominent, segments of the limb reflexed ; 

 stamens borne on small filaments inserted in the tube ; 

 anthers connivent and arrow-shaped ; style filiform 

 and protruding ; seed-vessel a berry, but opening at 

 last into five parts ; seeds seated in the pulp. These 

 plants were called sow-bread by the ancients, in allu- 

 sion to the tubers being sought for and eaten by hogs. 

 The Persian is the only greenhouse species, but all 

 deserve to be kept in pots, and placed where they 

 may be seen to most advantage. They yield abund- 

 ance of seeds by which they are easily increased, 

 provided the seed is sown soon as it is ripe. 



CYC LAS (Lamarck), TELLINA (Linnaeus). This 

 genus of molluscs has been separated from the genus 

 Tcllina, in consequence of certain well-defined distinc- 

 tion: these, nevertheless, though sufficient to separate 

 them from that genus, have led to some speculation on 

 the part of modern malacologists ; and we find in tho 

 French school that the genus Cyrena of Lamarck, the 

 genus Cornea and Corbicula of Megerle, and the 

 Galaihea of Cuvier, are all considered as subdivisions 

 .of the genus Cyclas , and though we do not advocate 

 an useless multiplication of genera, we cannot alto- 

 gether agree with that arrangement ; however, as the 

 general habits of these molluscs, as well as their 

 organisation, nearly correspond, we give the following 

 description in accordance to the French school : 

 The shells of this genus are small, of a very convex 

 oval form ; valves very thin, and always without 

 three primary teeth on either of them ; apices never 

 eroded or decorticated ; some species are so thin and 

 fragile as to be transparent ; the valves smooth or 

 transversely striated ; shell transverse, equivalve, 

 apices protuberant ; primary teelh very small, almost 

 obsolete, sometimes two on each valve, of which one 

 is plaited in the middle of the one valve, and some- 

 times two plaited or folded teeth on the other. These 

 constitute Lamarck's genus Cyclas. Such species as 

 have a suborbicular form, the cardinal teeth rather 

 variable, and always very small, if not altogether ob- 

 solete, with the apices not eroded, form the genus 

 Cornea of Megerle. The species of a subtrigonal, or 

 an elongated oval shape, having the apices eroded, 

 and more anterior, with three cardinal teeth, the two 

 posterior of which are bifid, constitute Lamarck's 

 genus Cyrena, and those having the lateral teeth 

 dentated, but corresponding in other respects, form 

 the genus Corbicula of Megerle. The species of a 

 subtrigonal form, with two-grooved cardinal teeth on 

 one valve, three on the other, the middle one being 

 larger and callous, form Lamarck's genus, Galathca. 

 All these molluscs inhabit fresh water, generally 

 buried in the mud ; the two last sections only are 

 known in Europe : the greater number of the others 

 being from the Indian rivers, but every part of the 

 world presents species of the first division; the shells 

 are generally provided with an epidermal coat. The 



animal has its body of an oval form, the edges of the 

 mantle plain, the tubes short and united, the foot 

 large, compressed at its base, and terminated by a 

 species of foot, or appendage answering that pur- 

 pose. This genus is classed in the third class Ace- 

 phalophora, third order Lamellibranchiata, eighth 

 family Conchacea. 



CYCLICA (Latreille). An extensive division of 

 coleopterous insects belonging to the' section Tetrn- 

 mera, distinguished by the generally short and rounded 

 form of the body. They differ from the Rkyncophora 

 or weevils, in not having the head produced into a 

 rostrum ; from the Xyhphaga, by having the antennae 

 not clavate ; from the Platysoma, by the body not 

 being flattened ; from the Longicornes, in the antenna; 

 being shorter than the body ; and from the Eitpoda, 

 in having the hinder part of the thorax as wide as the 

 base of the elytra. 



For the particular characters of this division as 

 well as for an account of the families of which it is 

 composed, we must refer to our article headed CHRY- 

 SOMELID.^, where, in consequence of this division 

 nearly corresponding with the Linnaean genus Chry- 

 somela, we have thought it more convenient to give 

 a description of this group. 



CYCLOBRANCHIATA is the name given to 

 an order of molluscs having the organs of respira- 

 tion branchial, in the form of tufts, more or less deve- 

 loped, symmetrically arranged near the vent, which is 

 situated in the median line of the posterior part of 

 the animal's body. The skin is naked, though some- 

 times intercalated. This order includes the genera 

 Don's, Onchidoris, and Peronia ; of the second class, 

 Paracephalophora. they will be described in their 

 respective places. 



CYCLOPS (Muller). A genus of minute aquatic 

 crustaceous animals, considered by M. Edwards as 

 entitled to the rank of an order, to which he has given 

 the name of Copepodd. These little creatures, which 

 abound in fresh and standing waters, are seldom more 

 than one-eighth of an inch long, and may constantly 

 be observed jerking about by the assistance of their 

 long tails. In their forms they somewhat resemble a 

 lobster in miniature, the thoracic part of the body 

 being of an oval form, furnished with a single eye in 

 front (whence the generic name of the group). This 

 part of the body is divided at its hinder part into 

 several segments, which are succeeded by an articu- 

 lated tail or abdomen, from the base of which in the 

 females depends on each side a large membranous 

 bag containing the eggs. The abdomen is forked at 

 its extremity, each division being furnished with 

 strong setae ; the upper antennas are very long and 

 multiarticulate, but the inferior are short and four- 

 jointed. The legs, which are very short, consist of 

 five pairs, each leg being divided into two cylindrical 

 branches. From their curious forms, great agility, 

 and odd motions, these little insects form conspicuous 

 objects in the exhibitions of the solar microscope, 

 with which instrument so much instruction and amuse- 

 ment is capable of being produced. The upper and 

 long antennae perform the offices of legs, and the 

 lower pair of these organs, from their being kept in a 

 continual rapid motion, produce a kind of whirlpool, 

 which brings into its vortex the minute particles upon 

 which they feed. At the period of coupling the 

 males are extremely active. The eggs which are of 

 a brown, blue or green colour, varying according to 

 their age, become transparent when nearly readv to 

 P'2 



