C Y A 



[ 67] 



C Y M 



ments splintery. It feels somewhat 

 greasy. Before the blow-pipe it becomes 

 almost perfectly white, but it does not 

 melt. Its constituent parts are, alumina 

 64-30, silica 34'33, with a trace of oxide 

 of iron and a very small portion of lime. 



CYA'THIFORM. (from cyathus and forma^ 

 Lat.) In the form of a cup, or drinking- 

 vessel ; cup-shaped. 



CYATHOPHY'LLOUS. (from KVO.BOQ, and 

 $vX\ov, Gr.) Having cup-shaped leaves. 



CYCA'DEA. (from KVKU^, cycas, Gr.) A 

 genus of plants. The cycadeae hold an 

 intermediate place between the palms, 

 ferns, and coniferse. Some species are 

 very short, as the zamia ; others attain a 

 height of thirty feet and upwards. This 

 beautiful family of plants in their exter- 

 nal habit resemble that of palms, whilst 

 their internal structure approximates to 

 that of coniferse. The cycadese are na- 

 tives of warm climates, mostly tropical, 

 though some are found at the Cape of 

 Good Hope. Leaves of cycadese are of 

 frequent occurrence in the shale of the 

 oolitic formation near Scarborough, and 

 they have been found in the Stonesneld 

 slate. Cycadese have been found in the 

 coal formation of Bohemia. The trunk 

 of the cycadea has no true bark, but it is 

 surrounded by a dense case, composed of 

 persistent scales, which have formed the 

 bases of fallen leaves ; these, together with 

 other abortive scales, constitute a com- 

 pact covering that supplies the place of 

 bark. The prevalence of cycadese gives 

 a distinctive character to the flora of the 

 upper secondary formations. The stems 

 found in the Isle of Portland, and the 

 leaves and fruits in the oolitic formations 

 of Yorkshire, show considerable analogy 

 to the existing forms of the tribe at the 

 Cape of Good Hope, in India, and Aus- 

 tralia. 



CYCA'DEOUS. Possessing the characters 

 of cycadese ; belonging to the genus cy- 

 cadea. 



CYCA'DITES. A name applied to some 

 fossil species of cycas. Our fossil cyca- 

 dites are closely allied by many remark- 

 able characters of structure to existing 

 cycadese. BucJcland. 



CY'CAS. (KVKCIQ, Gr.) A genus of plants, 

 belonging to the first natural order Palmse, 

 according to the first arrangement of 

 Linnseus, but subsequently placed among 

 the ferns. 



CY'CLAS. (pi. cyclades.) A genus of 

 lacustrines, or fresh- water bivalves. The 

 calciferous grit near Hastings is full of 

 cyclades, and several species of cyclas 

 occur, in myriads, in the shales and 

 clays of the Wealden formation. Mantell. 

 The cyclas is an ovato- transverse bi- 

 valve, not inflected on the fore part ; the 



hinge with three hinge -teeth and two 

 lateral teeth, compressed and rather re- 

 mote. Parkinson. 



While the cyclas of Europe is de- 

 scribed as small, thin, and horny, abound- 

 ing in ditches, ponds, and slow streams, 

 that of Asia is stated to be very large. 

 The cyclas is viviparous. 



CY'CLE. (from KVK\OQ, Gr. cycle, Fr. ciclo, 

 It. ) A round of years which go on from 

 first to last, and then return to the same 

 order as before ; a space in which the 

 same revolutions begin again. 



CY'CLOID. (from KVK\OC,, and eidoc., Gr. 

 cyclo'ide, Fr.) A geometrical curve ; 

 a figure made by the upper end of the 

 diameter of a circle, turning about a 

 right line. 



CYCLO'IDAL. Relating to a cycloid. 



CYCLOI'DIANS. (from /cw/cXoc, Gr.) The 

 fourth order of fishes according to the 

 arrangement of M. Agassiz. Families of 

 this order have their scales smooth and 

 simple at their margin, and often orna- 

 mented with various figures at the upper 

 surface. The salmon and herring are 

 examples. 



CYCLOI'DEAN. Belonging to the fourth 

 order of fishes, according to the arrange- 

 ment of M. Agassiz. The cycloidean and 

 ctenoidean orders succeeded the placoi- 

 dean and ganoidean. 



CY'CLOLITE. (from KVK\OQ and \i9og, Gr.) 

 Another name for madrepore. 



CYG'NET. (from cycnus, Lat.) A young 

 swan. 



CY'LINDER. (icvXivdpoc,, Gr. cylindrus, 

 Lat. cylindre, Fr. cilindro, It.) A solid, 

 formed by the revolution of a rectangular 

 parallelogram about one of its sides, so 

 that it is extended in length equally round, 

 and its ends or extremities are equal 

 circles. 



CYLI'NDRIC. ) Partaking of the nature of 



CYLINDRICAL. $ a cylinder ; having the 

 form of a cylinder ; having its circum- 

 ference round, of indeterminate length, 

 but of equal thickness throughout. 



CYLI'NDRIFORM. Of the form of a cylin 

 der ; round like a roller. 



CYLI'NDROID. A solid, in many respects 

 resembling a cylinder, but having ellipti- 

 cal instead of circular extremities, yet 

 parallel and equal. 



CYLINDRICO'DON. The name given to a 

 genus of oviparous quadrupeds. 



CYME, (cyma, Lat. KVjita, Gr.) 



1. A form of inflorescence, the general 

 appearance of which resembles an umbel, 

 and agrees with it in this respect, that its 

 common stalks all spring from one centre ; 

 but differs in having those stalks alter- 

 nately and variously divided. The olean- 

 der and elder are examples. 



2. A sprout, as of a cabbage. 



