COL 



CON 



mences at the coecurn, and terminates in 

 the rectum. 



COLO'PHONITE. A brown or red variety of 

 dodecahedral garnet, having a resino-ada- 

 mantine lustre ; it is chiefly found at 

 Arendal, in Norway. It consists of si- 

 lica 37-0, alumina 13-6, lime 29 0, oxide 

 of iron 7*4, magnesia 6'5, oxide of man- 

 ganese 4-0, water I'D. 



COLU'MBITE. A mineral ore, the ore of 

 columbium. 



COLU'MBIUM. A metal first discovered in 

 1801 in a mineral brought from North 

 America, from which it received its name. 

 It is of a dark grey colour, very dense, 

 and difficult of fusion. 



COLOME'LLA. (Lat.) In conchology, the 

 upright pillar in the centre of most of the 

 univalve shells. 



CO'LUMN. In botany the central point of 

 union of the partitions of the seed-vessel, 

 (that is in a capsule containing many 

 cells) to which the seeds are usually at- 

 tached. 



COLU'MNAR. Formed in columns ; having 

 the form of columns ; having the circum- 

 ference always circular, but the thickness 

 indeterminate. 



CO'MATE. (comatus, Lat.) Hairy. In 

 entomology, having the upper part of the 

 head, or vertex, alone covered with long 

 hairs. 



COMA'TULA. An existing species of the 

 family of Crinoidea. The comatula pre- 

 sents a conformity of structure with that 

 of the pentacrinite, almost perfect in 

 every essential part, except that the co- 

 lumn is either wanting, or at least re- 

 duced to a single plate. Peron states 

 that the comatula suspends itself by its 

 side arms fromfuci, and in this position 

 watches for its prey, and obtains it by 

 its spreading arms and fingers. Miller. 



COMB. ^ These words, thus differently writ- 



COMBE. > ten, appear to be of Saxon ori- 



COOMB. J gin. Ray gives the second as 

 a south and east country word, and de- 

 fines it to be a valley, " vallis utrinque 

 collibus msita." Lyell states it to be a 

 provincial name for a valley on the de- 

 clivity of a hill, and which is generally 

 without water. Buckland says, " the 

 term Combe is usually applied to that un- 

 watered portion of a valley, which forms 

 its continuation beyond, and above the 

 most elevated spring that issues into it ; 

 at this point, or spring-head, the valley 

 ends and the combe begins." A narrow 

 undulating ravine. 



COMBU'STIBLE. (Fr.) Having the qua- 

 lity of catching fire ; susceptible of fire. 



COMBU'STION. (combustion, Fr. combus* 

 Hone, It.) Consumption by fire; the 

 disengagement of light and heat which 

 accompanies chemical combination. 



CO'MMINUTE. (from comminuo, Lat.) To 



pulverise; to break into small portions; 



to grind. 

 COMMINU'TION. The act of pulverising, 



or breaking into small parts. 

 CO'MMISSURE. (commissure, Lat.) A 



joint, seam, or suture. 

 COMPA'CTED. (compactus, Lat.) Firmly 



pressed together ; closely pressed. 

 COMPA'CTLY. Closely; densely. 

 COMPRE'SSED. (compressus, Lat.) 



1. In botany, leaves are so termed when 

 flattened laterally. 



2. In conchology, having one valve flatter 

 than the other. 



COMPRESSIBILITY. The quality of being 

 brought into a smaller compass ; thus 

 air is compressible, water is not. 



COMPRE'SSIBLE. (compressible, Fr. che 

 pub essere compresso, It.) That may be 

 forced by pressure into a smaller space. 



COMPRE'SSURE. The force of one body 

 pressing against or upon another. 



CO'MPTONITE. A mineral thus named after 

 Lord Compton, who first brought it to 

 England, found in the erupted matter of 

 Vesuvius. 



CONCA'MERATED. (from concamero, Lat.) 

 Arched over ; vaulted. 



CONCAMERA'TION. (concameratio, Lat.) 

 An arched chamber. In conchology con- 

 camerations are those small chambers 

 into which multilocular shells are divided 

 by transverse septa, as in the nautilus, 

 ammonite, &c. 



CO'NCAVE. (concjavus, Lat. concave, Fr. 

 concavo, It.) Hollow, as the inner sur- 

 face of an egg-shell : opposed to convex ; 

 when the surface gradually declines to- 

 wards its centre, the centre being the 

 deepest point. 



CON'CAVENESS. Hollowness. 



CONCA'VITY. (concavite, Fr. concavila, It.) 

 The internal surface of a hollow spheri- 

 cal or spheroidal body. 



CONCA'VO-CO'NCAVE. Concave, or hollow, 

 on both sides. 



CONCA'VO-CO'NVEX. Having one side con- 

 cave, the other convex. 



CONCE'NTRIC. (concentrique, Fr. con- 

 centrico, It.) Having one common cen- 

 tre, as the coats of the onion ; running 

 to a centre. A term applied to the di- 

 rection taken by the lines of growth in 

 spiral bodies. 



CONCH, (concha, Lat. Koyxn> Gr.) A 

 marine shell. 



CONCHA. Shells consisting of two or more 

 pieces or valves, as bivalves, and multi- 

 valves. 



CO'NCHIFER. A class of mollusca, the con- 

 structors and inhabitants of bivalves. 

 All turbinated and simple shells are con- 

 structed by molluscs of a higher order 

 than the conchifers, which construct bi- 



